Journal articles on the topic 'Paper Dry strength Testing'
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Kiecana, Monika, Piotr Kanty, and Klaudia Łużyńska. "Optimal control time evaluation for “dry DSM” soil-cement composites." MATEC Web of Conferences 251 (2018): 01023. http://dx.doi.org/10.1051/matecconf/201825101023.
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Soil improvements with hydraulic binders are a widespread practice in foundation works. They vary depending on the mixing method (jet grouting hydraulic, deep soil mixing -mechanical), medium type (wet/water, dry/air) and binder type (cement, lime, fly ash or mixtures). The produced component’s strength changes in time thus its control should change in time as well. The paper presents the results of laboratory testing of an organic soil component mixed in dry method. The process of samples preparation and testing methodology of compressive strength and stiffness is described. Volatility of the parameters in time is considered. On the basis of the results, recommendation for optimal quality control time and its methodology for soil-cement components might be proposed.
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Jendrysik, Klaudia, Monika Kiecana, and Hubert Szabowicz. "Preliminary results of dry Deep Soil Mixing soil-cement composite testing." MATEC Web of Conferences 251 (2018): 01025. http://dx.doi.org/10.1051/matecconf/201825101025.
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This paper provides results of testing made for soil-cement mixtures in dry mixing technology. This technology is greatly dependent on existing soil condition; hence the results are of highly random nature. Material used in testing was distinguished with high organic content and low humidity. Tests were carried out in laboratory of Wroclaw University of Technology on 145 samples as ordered by Menard Polska Ltd. Company. Samples were prepared and stored under laboratory conditions and then, after various maturation time, were destroyed in a testing machine. The purpose was to determine the stress-strain curves used to find strength properties, strain at failure, modulus of elasticity, secondary modulus of elasticity versus cement content. Test confirmed improvement of soil strength properties after addition of cement binder. The results may be used to determine the most economic binder-to-soil ratio.
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Koukis, G., N. Sabatakakis, and S. Papanakli. "Laboratory testing properties of sandstones." Bulletin of the Geological Society of Greece 40, no. 4 (January 1, 2007): 1695. http://dx.doi.org/10.12681/bgsg.17083.
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The aim of this paper is to determine the geotechnical properties of clastic sedimentary rocks and especially sandstones which constitute a great part of the flysch formation. Laboratory tests were conducted in samples collected from different sites in western Greece. Physical and mechanical properties were determined including porosity (n), dry density (pf), sound velocities (Vp, Vs), point loading strength (IS(so)) and uniaxial compressive strength (ac). Additionally, the material constant m„ an input parameter for the Hoek and Brown failure criterion, was estimated by analyzing the results from a series of triaxial compression tests under different confining pressures. Regression analyses were also applied to define the relations among the obtained parameters
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Dobrowolska, Ewa, Mateusz Niedbała, and Daniel Tabaczyński. "Testing of the fatigue strength along wood fibres at different moisture contents." Annals of WULS, Forestry and Wood Technology 115 (September 26, 2021): 45–54. http://dx.doi.org/10.5604/01.3001.0015.5133.
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Testing of the fatigue strength along wood fibres at different moisture contents. The paper determines the effect of wood moisture content on the fatigue strength in compression along fibres. The method of determining the maximum stress at the proportional limit was used for the measurements. Fatigue strength was investigated for three wood species: pedunculate oak (Quercus robur L.), bearded birch (Betula pendula Roth.) and Norway spruce (Picea abies L.), with two moisture contents: close to the absolutely dry state and above the fibre saturation point. The ratio of fatigue strength to short term strength depends on moisture content and is similar for birch (70.3% in the dry state and 72.1% in the wet state), for oak (67.4% and 69.5% in both states) and for spruce (66.6% in the dry state and 68.1% in the wet state). The moisture content of the wood clearly influences the fatigue strength of the wood. On average, the fatigue strength of wood with moisture contents above the fibre saturation point constitutes about 0.20 of the fatigue strength of wood with moisture contents close to 0%. This tendency was found regardless of the tested species. The simplified method for testing fatigue strength at the limit of proportionality has shown its limited usefulness, requiring further analysis and comparison with other methods in order to be thoroughly tested and possibly improved.
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Varanasi, Swambabu, Hui Hui Chiam, and Warren Batchelor. "Application and interpretation of zero and short-span testing on nanofibre sheet materials." Nordic Pulp & Paper Research Journal 27, no. 2 (May 1, 2012): 343–51. http://dx.doi.org/10.3183/npprj-2012-27-02-p343-351.
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Abstract This paper investigates the use of zerospan testing to measure the tensile strength of cellulose nanofibre sheets. The mechanical strength of cellulose nanofibre paper is a key property but tensile strength measurement requires a substantial amount test material, whereas a zero/short span test needs much less material. Sheets made from cellulose nanofibres, microfibrillated cellulose (MFC) and northern bleached softwood fibres were tested at spans ranging from 0 to 0.6 mm and tensile strength spans of 50 and 100 mm. For the cellulose nanofibres or the MFC sheets, strength was constant with span from 0 to 0.6 mm when tested dry and negligible when tested wet, except at zero span. The sheets made from the softwood fibres showed significant strength when tested wet at all spans from 0 to 0.6 mm. The results showed that for nanofibre materials, the zero or short span strength is measuring sheet tensile strength at a smaller sample length. The strength of the nanofibre sheets at 50 or 100 mm was smaller than at zero/short span due to sample size effects and Poisson contraction. The effects of starch and grammage on strength were also studied.
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Wang, Chenfei, Zixiong Guo, and Ditao Niu. "Influence of the Fiber Volume Content on the Durability-Related Properties of Polypropylene-Fiber-Reinforced Concrete." Sustainability 12, no. 2 (January 11, 2020): 549. http://dx.doi.org/10.3390/su12020549.
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Polypropylene-fiber-reinforced concrete impacts the early shrinkage during the plastic stage of concrete, and the fiber volume content influences the durability-related properties of concrete. The purpose of this paper was to investigate the influence of fiber volume content on the mechanical properties, durability, and chloride ion penetration of polypropylene-fiber-reinforced concrete in a chloride environment. Tests were carried out on cubes and cylinders of polypropylene-fiber-reinforced concrete with polypropylene fiber contents ranging from 0% to 0.5%. Extensive data from flexural strength testing, dry–wet testing, deicer frost testing, and chloride penetration testing were recorded and analyzed. The test results show that the addition of the fiber improves the failure form of the concrete specimens, and 0.1% fiber content maximizes the compactness of the concrete. The flexural strength of specimen C2 with 0.1% fiber shows the highest strength obtained herein after freeze–thaw cycling, and the water absorption of specimen C2 is also the lowest after dry–wet cycling. The results also indicate that increasing the fiber volume content improves the freeze–thaw resistance of the concrete in a chloride environment. Chlorine ions migrate with the moisture during dry–wet and freeze–thaw cycling. The chlorine ion diffusion coefficient (Dcl) increases with increasing fiber content, except for that of specimen C2 in a chloride environment. The Dcl during freeze–thaw cycling is much higher than that during dry–wet cycling.
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POTTER, F. S., T. L. WRIGHT, C. HAGIOPOL, and J. W. JOHNSTON. "A new perspective on tissue wet strength decay: the real values." January 2013 12, no. 1 (February 1, 2013): 9–15. http://dx.doi.org/10.32964/tj12.1.9.
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The measurement of two key properties of bath tissue (paper wet strength after 5 s and 5 min of soaking in water) were performed on a broad selection of samples from retail shelves. The importance of the experimental errors and their distribution on the interpretation of the physical testing data is evaluated. Examining the data in this manner allows for a new way to look at the relationship between dry strength, initial wet strength, and the decay rate of the paper. The importance of chemistry is revealed and discussed, giving a new perspective with respect to paper properties and the strength relationships in tissue.
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Tamošiūnas, Tadas, and Šarūnas Skuodis. "Non-cohesive Soil Direct Shear Strength Affected with Hydrostatic Pressure." Mokslas - Lietuvos ateitis 9, no. 5 (December 27, 2017): 520–23. http://dx.doi.org/10.3846/mla.2017.1078.
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This paper presents first results of noncohesive soil direct shear tests with hydrostatic pressure. To reach this aim, it was chosen the Baltic Sea Klaipėda sand, due to granulometry composition and particles shape. According to this, investigated Baltic Sea sand can be called Lithuanian standard sand for scientific testing. Analysis of results revealed, that when it is increased hydrostatic pressure, the shearing strength is also increasing. Comparing air dry sand results with fully saturated sand and affected with 100 kPa of hydrostatic pressure, the angle of internal friction increased for 21,24%. Meanwhile, the cohesion was not changing so dramatically according to hydrostatic pressure change. Obtained results allows to proceed this research work more detailed with different loading types, testing procedures and hydrostatic pressures.
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Guan, Yongsheng, Zhixiang Zhang, Xiaorui Zhang, Junqing Zhu, Wen Zhou, Qi Huang, and Yuqing Zhang. "Effect of superabsorbent polymer on mechanical properties of cement stabilized base and its mechanism." Transportation Safety and Environment 2, no. 1 (April 2020): 58–68. http://dx.doi.org/10.1093/tse/tdaa001.
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Abstract Superabsorbent polymers (SAPs) are cross-linked polymers that can absorb and retain large amounts of water. In recent years, a growing interest was seen in applying SAPs in concrete to improve its performance due to its efficiency in mitigating shrinkage. This paper presents findings in a study on effect of SAPs on performance of cement-treated base (CTB), using the experience of internal curing of concrete. CTB specimens with and without SAPs were prepared and tested in the laboratory. Tests conducted include mechanical property testing, dry shrinkage testing, differential thermal analysis, mercury intrusion porosimetry and scanning electron microscope testing. It was found that 7-day and 28-day unconfined compressive strength of CTB specimens with SAPs was higher than regular CTB specimens. 28d compressive strength of CTB specimens with SAPs made by Static pressure method was 5.87 MPa, which is 27% higher than that of regular CTB specimens. Drying shrinkage of CTB specimens with SAPs was decreased by 52.5% comparing with regular CTB specimens. Through the microstructure analysis it was found that CTB specimens with SAPs could produce more hydration products, which is also the reason for the strength improvement.
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Lachance-Tremblay, Éric, Michel Vaillancourt, Daniel Perraton, and Hervé Di Benedetto. "Comparison of the moisture damage of bituminous binder coupled with glass and limestone substrate using pull-off test." Canadian Journal of Civil Engineering 46, no. 3 (March 2019): 188–94. http://dx.doi.org/10.1139/cjce-2018-0152.
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In this paper, the moisture susceptibility of different bituminous binders with two substrates (glass and limestone) was investigated. To that end, the tensile strength of different combinations of bituminous binder–substrate bond was measured using a pull-off test. This test was adapted from the pneumatic adhesion tensile testing instrument (PATTI) test to improve repeatability. Samples were tested in dry condition and after a 7-day conditioning in hot water bath (60 °C). An analysis of variance (ANOVA) was performed on the test results. Overall, the results show that in dry condition, the pull-off strength is a function of the bituminous binder type rather than of the substrate type. After water conditioning, an increase in the pull-off strength was observed for the bituminous binder without polymers and coupled with glass substrate. This was associated with an increase in binder stiffness. For the limestone substrate, the effect of water conditioning was significant only for one type of binder.
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Mahmood, Mohammed Sh, Waseem H. Al-Baghdadi, Asaad M. Rabee, and Suhad H. Almahbobi. "Reliability of Shear-Box Tests Upon Soaking Process on the Sand Soil in Al-Najaf City." Key Engineering Materials 857 (August 2020): 212–20. http://dx.doi.org/10.4028/www.scientific.net/kem.857.212.
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Accurate prediction of the soil shear strength parameters is essential in the reliable geotechnical design of civil engineering structures. This recent paper investigates the effect of the dry testing condition on the shear strength parameters of the sandy soil using the direct shear apparatus and compared with the saturated condition tests in previous researches on the same soil. The dry soil, usually above the water table, is the principal condition of the Al-Najaf city soil in Iraq. Samples are selected from the site of the University of Kufa, which represents the sandy soil of the city. For reliability purposes, the soil is exposed to different pre-soaking durations (one, two, and four weeks) then air-dried for shear tests. The main results revealed that the angle of internal friction (Φ) tested as a dry sample decreases about -6% up to two-weeks soaking then recovered upon four-week soaking about +6%. Compared to the saturated testing, there are increases in F between 6%-17% from saturated tests. Finally, it is recommended to aware in the selection of testing conditions for calculations of the angle of internal friction.
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Mužíková, Jitka, Alena Komersová, Václav Lochař, Lucie Vildová, Bára Vošoustová, and Martin Bartoš. "Comparative evaluation of the use of dry binders in a physical mixture or as a coprocessed dry binder in matrix tablets with extended drug release." Acta Pharmaceutica 68, no. 3 (September 1, 2018): 295–311. http://dx.doi.org/10.2478/acph-2018-0030.
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Abstract This paper evaluates and compares the properties of directly compressible tabletting materials and matrix tablets containing a combination of α-lactose monohydrate and microcrystalline cellulose in the 3:1 ratio in a physical mixture and in a coprocessed dry binder. Tested parameters include flow properties, compressibility, compactibility and the rate of drug release from tablets. Compressibility is evaluated by means of the energy profile of the compression process. Compactibility is evaluated by means of the tensile strength of the tablets. Dissolution testing is done using the rotating basket method. Dissolution profiles are evaluated by non-linear regression analysis. Total energy of compression and plasticity values were higher in tabletting materials with the coprocessed dry binder. Increasing additions of polyvinyl alcohol decreased the values of total energy of compression, plasticity, tensile strength of tablets and drug release rate. Dissolution behaviour of tablets, which contained the physical mixture or coprocessed dry binder and the same amount of polyvinyl alcohol, was comparable.
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Prakash A, Krishna, Jane Helena H, and Paul Oluwaseun Awoyera. "Optimization of Mix Proportions for Novel Dry Stack Interlocking Concrete Blocks Using ANN." Advances in Civil Engineering 2021 (June 21, 2021): 1–15. http://dx.doi.org/10.1155/2021/9952781.
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This paper proposes novel concrete interlocking blocks made of fly ash and GGBS which are an alternative for the conventional concrete blocks. The artificial neural network (ANN) technique is used to estimate the mechanical strength of interlocking blocks and is verified with experimental investigation. The ANN model is based on the Levenberg–Marquardt principle which is executed using MATLAB. The inputs are given in the percentage ratio of cement: fly ash: crushed stone aggregate (FA): coarse aggregate (CA) for the process of learning, testing, and validation. The selected model is subjected to several trials in terms of mean square error, containing 4 input, 2 sets of 10 hidden layers, and one output components. In this study, a total of 2600 blocks of different mixes were tested as per IS 2185-1 (2005) to assess 3, 7, 14, 21, and 28 days’ strength. The experimental investigations were carried out in two phases. In the first phase, experimental investigations to identify the optimum mix proportions of cement, aggregate, fly ash, and ground granulated blast furnace slag to achieve desired compressive strength was carried out. In the second phase, the identified mix proportions were analysed using ANN to predict the compressive strength of interlocking blocks. The results indicate that the proposed ANN model developed to determine the mechanical strength and cost of interlocking blocks has excellent prediction ability.
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Kanty, Piotr, Monika Kiecana, and Piotr Prokopowicz. "Some remarks on statistic approach to strength testing of soil-cement composites." E3S Web of Conferences 97 (2019): 04045. http://dx.doi.org/10.1051/e3sconf/20199704045.
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Results of laboratory testing of organic soil-cement samples are presented in the paper. The research program continues on the authors previously reported experiences with cement - organic soil sample testing. Over 150 compression tests have been carried out altogether. Several samples were cured for over 3 months before they were tested. Several factors, such as: the large amount of the pieces under test, long observation time, carrying out the tests in complex cycles of loading and the possibility of continuous registering the loads and deformation in the axial direction – made it possible to control numerous interdependencies, some of which have been presented in this work. Compressive strength and elastic modulus of cubic samples were examined. Samples were mixed and stored in laboratory conditions. The results clearly point to the fact that designing the DSM dry columns in the organic soil may be linked with a considerable risk and needs special precautions. During in situ mixing, the organic material surrounded by sand layers surely mixes with one another in certain areas. However, it has not been examined and it is difficult to assume such mixing already at the designing stage.
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Santana, Teresa, João Gonçalves, Fernando Pinho, and Rui Micaelo. "Effects of the Ratio of Porosity to Volumetric Cement Content on the Unconfined Compressive Strength of Cement Bound Fine Grained Soils." Infrastructures 6, no. 7 (June 26, 2021): 96. http://dx.doi.org/10.3390/infrastructures6070096.
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This paper presents an experimental investigation into the effects of porosity, dry density and cement content on the unconfined compressive strength and modulus of elasticity of cement-bound soil mixtures. A clayey sand was used with two different proportions of type IV Portland cement, 10% and 14% of the dry mass of the soil. Specimens were moulded with the same water content but using four different compaction efforts, corresponding to four different dry densities. Unconfined compression testing was conducted at seven days of curing time on unsoaked samples. The results showed that the compressive strength increased with the increase in cement content and with the decrease in porosity. From the experimental data, a unique relationship was found between the unconfined compressive strength and the ratio of porosity to volumetric cement content for all the mixtures and compaction efforts tested. The equation developed demonstrates that it is possible to estimate the amount of cement and the dry density to achieve a certain level of unconfined compressive strength. A normalized general equation was also found to fit other authors’ results for similar soils mixed with cement. From this, a cement-bound soil model was proposed for the development of a mixing design procedure for different soils.
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Zhang, Junran, Lijin Wang, Tong Jiang, Miao Ren, and min Wei. "Diametric splitting tests on unsaturated expansive soil with different dry densities based on particle image velocimetry technique." Acta Geotechnica Slovenica 18, no. 1 (2021): 15–27. http://dx.doi.org/10.18690/actageotechslov.18.1.15-27.2021.
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There is a close relationship between tensile strength of soil and crack development, but the tensile stress-strain in full failure process is rarely studied because challenges exist in accurately measuring shear strain using traditional methods. In this paper, we employed a newly developed diametric splitting testing apparatus and particle image velocimetry (PIV) system to study the tensile strength of compacted unsaturated expansive soil with different water contents and initial dry densities. Soil water characteristic curves of compacted expansive soil with different initial dry densities were determined using the filter paper method. Test results show that the tensile strength increases first and then decreases with increasing water content, and there is a critical water content for the peak load vs. water content curve. The diametric splitting test process can be divided into four stages on the basis of the plotted load-displacement curves: a stress contact adjustment stage (I); stress approximately linear increasing stage (II); tensile failure stage (III); and residual stage (IV). Under the same water content, the angle between the major directions of the displacement vector and the major crack decreases with increasing the dry density, especially when the fissure appears. Using the particle image velocimetry technique, the displacement and strain during the test process recorded is helpful for better understanding the soil failure mechanism.
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Lemenkov, V., and Polina Lemenkova. "Testing Deformation and Compressive Strength of the Frozen Fine-Grained Soils with Changed Porosity and Density." Journal of Applied Engineering Sciences 11, no. 2 (December 1, 2021): 113–20. http://dx.doi.org/10.2478/jaes-2021-0015.
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Abstract Current paper focuses on the laboratory experiments performed wit aim to test the deformation in the frozen loam soil specimens. Loam frozen soils are subject to the external effects, such as climate and environmental impacts including temperature changes. Soil heave is one of the key features restraining possible area development: construction of buildings, roads and railways. Necessarily, this requires the improvements of methods of the assessment of heave. This research evaluated the compressive strength and deformation in several specimens of the frozen soil. The approach included varying load and physical properties of soil specimens: porosity, pore filling, moisture, density of soil particles and dry soil density. Besides during the experiment, the external conditions were changed: decreased temperature and increased load pressure. The experiment is based on the UPG-MG4-01. The paper presented the laboratory tests of heave and compressive strength of the frozen soils using applied geotechnical methods.
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Zha, Xiao Xiong, and Kai Zhang. "The Experiment and Theoretical Analysis of Reusing Waste Cement Mortar." Applied Mechanics and Materials 71-78 (July 2011): 3595–99. http://dx.doi.org/10.4028/www.scientific.net/amm.71-78.3595.
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This paper presents the idea of mixing waste cement mortar into foam concrete block, and gets the foam concrete testing models with the values of dry density at 700 to 1000 kg/m3 , and the compression strength at 0.5-2.5MPa, which are met to foam concrete block standard. At the same time, the power formulas for calculating the dry density and compression strength of concrete cubes doped with waste cement mortar have been brought up, which are coincided with the experiment results well. An initial discussion about microcosmic composition has also been given, which has rather high practical application values since it offers experimental and theory foundations for reusing the waste cement mortar. The innovation significance should not be neglected, since it is the first time doing research on these aspects.
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Ismaili, Gaddafi, Badorul Hisham Abu Bakar, and Khairul Khuzaimah Abdul Rahim. "The Behavior of Strength Properties from Three Different Tree Boles of Aras in Sarawak." Journal of Civil Engineering, Science and Technology 2, no. 2 (December 1, 2011): 48–52. http://dx.doi.org/10.33736/jcest.94.2011.
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Aras had been selected and tested in small clear specimens. Sampling of test specimens are made from three sections of the tree bole namely from bottom, middle, and top parts. This paper looks into the information of strength properties from three sections of sampled. The strength properties test required are the modulus of rupture, modulus of elasticity and compression stress parallel to grain. Meanwhile, the physical properties' test referred to moisture content and basic density. The testing conducted in two different conditions of the trees, which were referred to green and air-dry condition. It was found that the average mean values for modulus of rupture, modulus of elasticity and compressive stress parallel to grain tested at green condition were 47.52N/mm2, 6358.56N/mm2 and 22.42N/mm2 respectively meanwhile at air-dry condition were 70.49N/mm2, 8217.64N/mm2 and 34.07N/mm2 respectively. Meanwhile, the average mean values for moisture content at green condition were 83.34% whilst at the air-dry condition were 12.33%. Basic density remains unchanged from both conditions.
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Yu, Li Ming, Zhe An Lu, Xiao Hui Yuan, and Hui Guo Chen. "Mixture Ratio Design of Inorganic Polymer Concrete and the Study of Expansive Performance." Applied Mechanics and Materials 357-360 (August 2013): 1142–47. http://dx.doi.org/10.4028/www.scientific.net/amm.357-360.1142.
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norganic polymer concrete of a new environment-friendly material has been the hot issue in engineering research so far. For this new material, the main job of the paper includes: we design mixture ratios of inorganic polymer concrete by ourselves, testing the concrete in the age periods of 3, 7, 28 d. The results indicate that this kind of material strength develops mainly in the first 3 d, the strength grows slowly in the later stage; the dry shrinkage of the configured concrete properties are measured, the curve of dry shrinkage shows that the dry shrinkage occurs mainly in the first 14 d and develops slowly in the late; And measure the expansion performance of the concrete member mixed the different categories expansive agent, the results show that the volume growth of mortar specimens to join HCSA expansion agent are obvious; Test results provide a certain basis for the inorganic polymer concrete of micro expansion.
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Lai, Yong, Yan Liu, and Dao Xun Ma. "The Influence of Preparation Method and Electrode on Properties of Carbon Fiber Electrically Conductive Concrete." Applied Mechanics and Materials 584-586 (July 2014): 1035–38. http://dx.doi.org/10.4028/www.scientific.net/amm.584-586.1035.
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This paper studied the influence of preparation method and electrode on properties of carbon fiber electrically conductive concrete by testing flexural strength and electrical resistance. Carbon fiber electrically conductive concrete is prepared by using dry mix method and wet mix method, the electrodes of which are stainless steel mesh and stainless steel sheet. The results show that the wet mix method of carbon fiber electrically conductive concrete is better than the dry mix method. The stainless steel sheet used as electrode in electrically conductive concrete is better than the stainless steel mesh. The long-term electrical resistivity of carbon fiber electrically conductive concrete is a constant value.
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Hussein, A., Z. M. R. Abdul Rasoul, and A. J. Alsaad. "Steel Fiber Addition in Eco-Friendly Zero-Cement Concrete: Proportions and Properties." Engineering, Technology & Applied Science Research 12, no. 5 (October 2, 2022): 9276–81. http://dx.doi.org/10.48084/etasr.5178.
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The main objective of this paper is to study the behavior of eco-friendly zero-cement concrete, its proportions, and its properties. The experimental program involves casting and testing many specimens divided into three main groups according to the percentage of added steel fibers in order to investigate the effect of steel fibers on the density, compressive strength, modulus of elasticity, and splitting tensile strength of concrete. The experimental outcomes indicated that the percentage of steel fibers has a small impact on the dry density: adding 0.5% and 1% of steel fibers increased the dry density by about 0.9% and 1.6% respectively. The percentage of steel fibers has an important impact on the compressive strength: after 28 days, steel fibers increased the compressive strength by about 4.9% and 12.8% for added steel fiber percentages of 0.5% and 1%. Also, the results indicated that steel fiber had an important impact on the splitting tensile strength in concrete after 28 days of curing: adding 0.5% and 1% steel fibers increased the splitting tensile strength by about 11.8%and 23.2% respectively. Finally, adding steel fibers has an impact on the modulus of elasticity: after 28 days, adding 0.5% and 1% steel fibers improved the modulus of elasticity approximately by 1.7% and 5%.
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Mysore, Tajammul Hussain M., Arun Y. Patil, G. U. Raju, N. R. Banapurmath, Prabhakar M. Bhovi, Asif Afzal, Sagr Alamri, and C. Ahamed Saleel. "Investigation of Mechanical and Physical Properties of Big Sheep Horn as an Alternative Biomaterial for Structural Applications." Materials 14, no. 14 (July 20, 2021): 4039. http://dx.doi.org/10.3390/ma14144039.
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This paper investigates the physical and mechanical properties of bighorns of Deccani breed sheep native from Karnataka, India. The exhaustive work comprises two cases. First, rehydrated (wet) and ambient (dry) conditions, and second, the horn coupons were selected for longitudinal and lateral (transverse) directions. More than seventy-two samples were subjected to a test for physical and mechanical property extraction. Further, twenty-four samples were subjected to physical property testing, which included density and moisture absorption tests. At the same time, mechanical testing included analysis of the stress state dependence with the horn keratin tested under tension, compression, and flexural loading. The mechanical properties include the elastic modulus, yield strength, ultimate strength, failure strain, compressive strength, flexural strength, flexural modulus, and hardness. The results showed anisotropy and depended highly on the presence of water content more than coupon orientation. Wet conditioned specimens had a significant loss in mechanical properties compared with dry specimens. The observed outcomes were shown at par with results for yield strength of 53.5 ± 6.5 MPa (which is better than its peers) and a maximum compressive stress of 557.7 ± 5 MPa (highest among peers). Young’s modulus 6.5 ± 0.5 GPa and a density equivalent to a biopolymer of 1.2 g/cc are expected to be the lightest among its peers; flexural strength 168.75 MPa, with lowest failure strain percentage of 6.5 ± 0.5 and Rockwell hardness value of 60 HRB, seem best in the class of this category. Simulation study identified a suitable application area based on impact and fatigue analysis. Overall, the exhaustive experimental work provided many opportunities to use this new material in various diversified applications in the future.
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Vacenovska, Bozena, and Rostislav Drochytka. "Development of a New Reclamation Material by Hazardous Waste Solidification/Stabilization." Advanced Materials Research 446-449 (January 2012): 2793–99. http://dx.doi.org/10.4028/www.scientific.net/amr.446-449.2793.
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This paper deals with the possibility of hazardous waste solidification/stabilization (S/S) using a secondary raw material – fly ash from fluidized bed combustion – in order to find and verify a suitable S/S formula and an appropriate way to ensure that the properties of the S/S product will allow its further use in civil engineering as a reclamation material. The aim of this paper is to examine the properties of the S/S product and to assess its impact on the environment. Laboratory testing was focused on screening those properties that may adversely affect the environment during the use of the product on the ground surface. During laboratory testing the S/S product’s properties were verified using leaching tests, unconfined strength testing, ecotoxicological tests and the determination of pollutant content in dry matter. This paper also considers the two-year durability of the S/S product’s properties in order to verify the short-term durability of the S/S matrix.
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Gasem, Zuhair M. "Environmental Degradation of Flexural and Fracture Properties of Glass/Vinyl Ester Filament Wound Pipes." Key Engineering Materials 334-335 (March 2007): 501–4. http://dx.doi.org/10.4028/www.scientific.net/kem.334-335.501.
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An experimental testing program is being conducted to evaluate the effects of environmental exposure on the mechanical properties of glass/vinyl ester filament wound pipes. The effects of artificial exposure on the flexural and fracture properties are reported in this paper. Three point bending specimens were employed to characterize the flexural properties. Fracture resistance was assessed using pre-cracked notched ring specimens. Specimens were exposed for 300, 1000, and 3000 hours in the environment of interest before testing at room temperature. The exposure conditions presented in this paper include: dry heat at 40 C, dry heat at 70 C, 65% and 100% relative humidity at room temperature; and salt spray and seawater environments at room temperature. The results of this study indicate that the flexural strength and stiffness; and the fracture resistance of the tested GFRP composite do not show significant degradation due to prior exposure to the environments investigated for up to 3000 hours. The flexural ductility is shown to degrade after exposure in high humidity environment.
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Richterova, Kristyna, Pavel Heinrich, and Petr Bíly. "Determination of Initial Shear Strength of Masonry Testing of Selected Adhesives." Solid State Phenomena 336 (August 30, 2022): 217–22. http://dx.doi.org/10.4028/p-643dhn.
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The following paper deals with the comparison of characteristic initial shear strength of masonry specimens made of innovative Heluz bricks and selected adhesives. The characteristic initial shear strength of masonry was determined according to ČSN EN 1052-3. Five different adhesives were tested in total. The characteristic initial shear strength of masonry was also researched depending on the amount of applied adhesive – this was determined for two adhesives. The specimens were made of three shaped bricks and a defined adhesive. Twenty-one large specimens were produced in total and they were put to the shear test in the age of one day. Adhesives available on the Czech market and foreign adhesives were tested. Selected adhesives were applied to the bed joints of bricks according to the usual standards. The produced specimens were stayed overnight in the production hall of the Heluz brick plant in Dolní Bukovsko and tested in the age of one day in the laboratory according to stated methods in appropriate norm. This paper deals with procedure of preparation of specimens, the course of the test and comparison of gained results.
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Khan, Shahzad, Sohit Agarwal, and Mukesh Pande. "An Experimental Investigation of Sustainable Concrete by using Paper Pulp and Crusher Dust." International Journal of Innovative Technology and Exploring Engineering 10, no. 3 (January 10, 2021): 1–6. http://dx.doi.org/10.35940/ijitee.c8328.0110321.
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The objective of the research carried out in this paper highlights the critical sustainability parameter of reusability of waste materials in the construction sector of India. This paper followed firstly the intense literature survey to identify the waste materials for the replacement in the concrete mix, hereafter Paper Pulp (P.P) and Crusher Dust (C.D) indicates the similar nature like cement and sand respectively. Secondly, an assumed proportion of replacement of P.P by 2.5%, 5%,7.5%,10%, and 12.5% by cement, and 10%, 20%, and 30% replacement of C.D by sand is adopted in M20 mix design by volume method. Thirdly, the casting of 48 sample cubes size of 150 mm × 150 mm × 150 mm is performed for Average Compressive Strength test, and casting of 48 cylindrical cubes of 150 mm in diameter and 300 mm long for Split Tensile Strength. Fourthly, the results are carried out for 7th day testing along with 28th day testing for both tests along with slump variation of different samples. It is observed after the experimental analysis that the elite results compared to normal M20 mix are exhibited when the replacement variation of P.P is 5% along with 10% variation of C.D for both Average Compressive Strength and Split Tensile test. In addition to it, the highest slump is obtained for replacement variation of 12.5% P.P and 10%C.D.
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Cabalar, Ali Firat, Sarwar Omer Hama, and Suleyman Demir. "Behaviour of a Clay and Gravel Mixture." Baltic Journal of Road and Bridge Engineering 17, no. 1 (March 28, 2022): 98–116. http://dx.doi.org/10.7250/bjrbe.2022-17.553.
Full textAbstract:
In most construction works, crushed rock aggregates with angular shape are used as subgrade materials. However, naturally available rounded granular aggregates could be utilized in design of subgrade layers as an alternative material for economic and environmental reasons. Therefore, a comparative study on the road pavement subgrade using aggregates of two different shapes (angular and rounded) of the same size (10–19 mm) has been conducted in this paper. The California Bearing Ratio and unconfined compressive strength tests were carried out on the mixtures of clay and different contents (0%, 5%, 10%, 15%, and 20% by dry weight) of both aggregates in order to evaluate the influence of the shape of these aggregates on the testing results. It was found that the mixtures with the rounded gravels showed a greater maximum dry density, unconfined compressive strength and CBR value, as well as lower optimum water content value, than those with the angular gravels.
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Velasquez, L. M., R. S. Sergent, J. O. Burgess, and D. E. Mercante. "Effect of Placement Agitation and Placement Time on the Shear Bond Strength of 3 Self-etching Adhesives." Operative Dentistry 31, no. 4 (July 1, 2006): 426–30. http://dx.doi.org/10.2341/05-52.
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SUMMARY This study measured the shear bond strength (SBS) of 3 self-etching bonding agents to enamel and dentin with and without agitation at 3 different application times. The null hypotheses tested were that agitation and application time have no effect on bond strength. Occlusal surfaces of 180 recently extracted caries-free human molars were wet ground with 600 grit wet-dry silica carbide abrasive paper to obtain a flat enamel surface. The teeth were divided into 18 groups of 10 teeth. Three self-etching bonding agents, Clearfil SE BOND (Kuraray America), Xeno III (Dentsply) and AdheSE (Ivoclar-Vivadent) were applied using application times of 10, 20 or 30 seconds with or without agitation, thinned with a gentle stream of air and cured for 10 seconds, according to manufacturers' directions. Z100 (3M ESPE) composite, A2 shade, was placed over the cured adhesive and cured for 40 seconds. The samples were stored in distilled water at room temperature until testing. The samples were tested in shear to failure with a 1-mm/minute crosshead speed. After enamel shear bond strength testing, the teeth were again ground with 400 and 600-grit wet-dry SiC paper to obtain a flat dentin surface. The protocol used for preparing the enamel bond test samples was repeated, and the teeth were stored until testing in distilled water at room temperature. The samples were again tested in shear at a 1-mm/minute crosshead speed. Values were converted to MPa and data analyzed for intergroup differences using ANOVA and Tukey post-hoc tests. Agitation did not improve enamel SBS for any of the materials tested, but there was a significant difference in enamel SBS among materials: Clearfil SE Bond shear bond strength was greater than Xeno III, which was greater than AdheSE. At 10 seconds application time on dentin, agitation improved the Clearfil SE Bond SBS and, at 20 seconds application time on dentin, agitation significantly improved SBS to dentin for all systems tested. Agitation had no affect when the adhesive was applied to dentin for 30 seconds. Clearfil SE Bond SBS to dentin was significantly higher than the other self-etching adhesives tested except at 10 seconds without agitation.
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Fu, Peng, and Guo Zhong Li. "Fluorine Gypsum Modification and Preparation of Self-Leveling Material." Applied Mechanics and Materials 711 (December 2014): 133–36. http://dx.doi.org/10.4028/www.scientific.net/amm.711.133.
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The fluorine gypsum was used as research object in this paper. In order to recognize the basic properties of fluorine gypsum fully, the physical and chemical properties were analyzed through different testing means. The chemical modification (additive A, sodium sulfate, quick lime) on the activity of fluorine gypsum excitation effect were studied. The best way to compound modification was determined and the mechanism of the admixture was analyzed. On this basis, the fluorine gypsum base self-leveling mortar materials was prepared and its performances were tested. Research shows that, the optimal ratio of: additive A content 2.0% (mixed), sodium sulfate content 0.8%, quick lime content 1.5%, the fluorine gypsum self-leveling material initial setting time is 2.4h, the final setting time is 5.3h, 24h flexural strength of 2.60MPa, compressive strength of 6.05MPa, the dry flexural strength of 7.68MPa, compressive strength of 22.89MPa, the performance indicators have reached the JC/T1023-2007《Gypsum based self-leveling mortar》 requirements.
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Zhao, Fang, Kun Lin Song, Wei Gao, and Shuang Bao Zhang. "Study on Preparation and Properties of Recycled Plastic-Poplar Plywood." Applied Mechanics and Materials 121-126 (October 2011): 2917–21. http://dx.doi.org/10.4028/www.scientific.net/amm.121-126.2917.
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In this paper, traditional adhesives were replaced by recycled plastics to make poplar plywood by hot-pressing. The results showed that the amount of recycled plastics made no obvious effects on the bonding strength, and the dry bonding strength reached the maximum with the amount of plastic film of 100g/m2. When the hot temperature was 150°C, the bonding strength no longer increased with the temperature, or even decreased. When the pressing time was 5 minutes, the bonding strength achieved the peak value, and then declined along with the extending of time. After testing, formaldehyde emission was found to be very low or zero. The new plywood is a kind of green and environmentally friendly wood-based panels. Above all, it could be concluded that the amount of plastic film of 100g/m2, the hot pressing temperature of 150°C and the hot pressing time of 5 minutes were the optimum process conditions in this experiment.
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Штенгель and Vyacheslav Shtengel. "Practical Application of a Complex of NDT Methods for Assessment of Oiled Reinforced Concrete Structures." NDT World 19, no. 4 (December 15, 2015): 72–75. http://dx.doi.org/10.12737/23512.
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The paper provides the results of the investigation into transformer-oiled reinforced concrete structures that has been carried out alongside with using an elastic recoil method, ultrasonic testing, and a breaking-off and chipping method. To ensure correct results, testing was applied to the adjacent oiled and dry areas of each structure. The results of all testing methods were found close to each other with regard to all data information obtained in the oiled and dry areas, i.e. no significant tendency in changing the concrete strength was noted when concrete was oiled with transformer oil. The investigation showed that traditional belief in the negative effect of oiling the concrete on physical and mechanical properties of the material is not true, at least for the transformer oil. One can assume that the oil effect on the concrete depends on the type of oil, composition (type of cement and fillers, water-to-cement content, etc) and cement structure (number of pores and microcracks), structure application environment condition, and the structure age prior to oiling, etc. Respectively, it requires a more detailed study into oiled structures in each specified case.
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Kujawski, M., L. Church, and W. Crawford. "Use of ASTM D8058 Flexural Strength Test Method to assess overall GCCM performance." IOP Conference Series: Materials Science and Engineering 1260, no. 1 (October 1, 2022): 012045. http://dx.doi.org/10.1088/1757-899x/1260/1/012045.
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Abstract ASTM D8058, a flexural strength test, is currently used as the main index test for Geosynthetic Cementitious Composite Mats (GCCMs) within Factory Production Control and is also used to assess comparative performance of GCCMs for durability and chemical resistance testing. This paper provides an overview of the suitability of ASTM D8058, three-point flexural strength test as an indicative method for assessing overall GCCM performance. Specifically, this paper will look at the relationship between GCCM Initial Flexural Strength (IFS) values obtained using ASTM D8058 and characteristics associated with the cementitious fill material. It also recommends further research to assess the relationship between Final Flexural Strength (FFS) values and characteristics associated with the geosynthetic components of the GCCM. IFS is obtained at the end of the first stage of a three-point bending test in the form of the first peak that is observed when the cementitious material first cracks in the tested specimen. The value of that first peak is mainly governed by the strength of the cementitious component of the GCCM. The relationship between IFS and the following GCCM properties is examined: Dry (uncured) mix density, Hardened (cured) density, Comressive strength development, Resistance to abrasion, Freeze and thaw durability and Resistance to chemicals.
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Li, Guo Hua, Shu Jiang Chen, and Lin Tian. "Study on MgO-MgO•Al2O3 Bricks Used Burned Zone of Cement Rotary Kiln." Advanced Materials Research 291-294 (July 2011): 3255–58. http://dx.doi.org/10.4028/www.scientific.net/amr.291-294.3255.
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The effects of iron scales and high iron magnesite as well as the content on microstructure and properties of MgO-MgO·Al2O3 bricks used burned zone of large cement rotary kilns have been studied. It focuses on testing coating adherence in this paper. The results show that apparent porosity of adding iron scales sample is higher than the sample by adding high iron magnesite, which is increased with increasing of iron scales content; Compression strength is decreased with increasing of iron scales content, The high iron magnesia cause the irregular change of the compression strength, compression strength was maximum when high iron magnesite content of additive was 6%; Coating adherence was optimum adding 3% high iron magnesite, adding 3% iron scales is followed, any other is bad. Over all, the sample adding 3% high iron magnesite is more suitable for large dry method cement kiln burned zone．
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Skuodis, Šarūnas, Gintaras Žaržojus, Tadas Tamošiūnas, and Neringa Dirgėlienė. "Reconstruction of Holocene marine sand natural hydrostatic pressure and its relation with shearing strength." Baltica 32, no. 2 (December 16, 2019): 182–89. http://dx.doi.org/10.5200/baltica.2019.2.5.
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This research paper represents interpretation of engineering geological and geotechnical conditions by using a direct shear device with a possibility to apply hydrostatic pressure during the experimental testing. In the authors’ opinion, the evaluation of in-situ hydrostatic pressure and reconstruction of it in the laboratory tests is a very important step in the determination of the engineering geological and geotechnical properties of the sand strength and its behaviour. To understand the influence of hydrostatic pressure on shearing strength results, there were performed direct shear tests with and without hydrostatic pressure. Obtained results clearly show the differences in the shearing strength analysed during this study. When the investigated sand sample was loaded with maximum hydrostatic pressure (σH = 100 kPa), the peak value of the angle of internal friction (ϕ’mean) was 21.24% higher compared to that of dry soil. No tendencies were found for cohesion.
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Самокрутов, Andrey Samokrutov, Шевалдыкин, and Viktor Shevaldykin. "Impact Induced Damage Detecting of Aircraft CFRP Covering by Acoustic Testing." NDT World 19, no. 4 (December 15, 2015): 29–32. http://dx.doi.org/10.12737/23501.
Full textAbstract:
Aircraft parts made of composite materials are susceptible to impact damage which can be negligible visually but significantly worsening their strength.
Finding such damage requires periodic monitoring of large areas of the surface of the aircraft airframe. Fundamentally, such monitoring is possible by using active thermography or acoustic methods.
Acceptable to practice, this task can be solved by scanning the surface with a rolling dry-point contact transducer array, and by analysis of Lamb wave signals propagating through the monitored material between the array adjacent transducers.
This paper presents a device based on this principle, the signal analysis algorithm, and the images recomposed by the device during composite material testing.
The developed equipment provides on-line inspection of impact-induced damage in aircraft covering made of composite materials. However, complex type of generated images requires constant monitoring of the covering state of each aircraft during its operation.
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Kamińska, J., and A. Kmita. "Reclaiming Ability of Spent Sands with Modified, Hydrated Sodium Silicate." Archives of Foundry Engineering 14, no. 1 (March 1, 2014): 41–44. http://dx.doi.org/10.2478/afe-2014-0010.
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Abstract The presented in the paper investigations were aimed at the determination of the reclaimed material (obtained in the dry mechanical reclamation process) addition influence on properties of moulding sands with hydrated sodium silicate modified by colloidal suspension of zinc oxide nanoparticles in propanol. Nanoparticles originated from the thermal decomposition of alkaline zinc carbonate, were used. The results of the reclamation of the spent moulding sand with hydrated sodium silicate performed in the AT-2 testing reclaimer are presented in the paper. Both, spent sands from the Floster S technology and from the technology with the modified water-glass were subjected to the reclamation processes. The following determinations of the reclaimed material were performed: pH reaction, acid demand, ignition loss and Na2O content. The obtained reclaim was used as a matrix component of moulding sands with water-glass in the Floster S technology, in which it constituted 60% and 50% of the sand matrix. The strength properties of the prepared moulding sands were determined (bending strength Rgu, tensile strength Rm u) after samples storing times: 1h, 2h, 4h and 24 hours.
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Shukla, Jigyasa, and Harsh Gupta. "STUDY AND ANALYSIS OF EFFECT OF STRENGTH PROPERTIES IN CALCINED KAOLIN AND SILICA FUME." International Journal of Research -GRANTHAALAYAH 8, no. 6 (July 14, 2020): 263–69. http://dx.doi.org/10.29121/granthaalayah.v8.i6.2020.575.
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This paper present the study of various strength such as compressive strength, split tensile strength and flexural strength during 7 and 28 day. It is construct the specimens size 15cm X 15cm X 15cm for testing purpose which depend upon the size of aggregate. Test results are indicated that strength performance of concrete well as in durability aspect are improved using of Silica fume
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Zhu, Xun, Nathan Liu, Michael J. Yaszemski, and Lichun Lu. "Effects of Composite Formulation on Mechanical Properties of Biodegradable Poly(Propylene Fumarate)/Bone Fiber Scaffolds." International Journal of Polymer Science 2010 (2010): 1–6. http://dx.doi.org/10.1155/2010/270273.
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The objective of our paper was to determine the effects of composite formulation on the compressive modulus and ultimate strength of a biodegradable, in situ polymerizable poly(propylene fumarate) (PPF) and bone fiber scaffold. The following parameters were investigated: the incorporation of bone fibers (either mineralized or demineralized), PPF molecular weight, N-vinyl pyrrolidinone (NVP) crosslinker amount, benzoyl peroxide (BP) initiator amount, and sodium chloride porogen amount. Eight formulations were chosen based on a resolution III two-level fractional factorial design. The compressive modulus and ultimate strength of these formulations were measured on a materials testing machine. Absolute values for compressive modulus varied from 21.3 to 271 MPa and 2.8 to 358 MPa for dry and wet samples, respectively. The ultimate strength of the crosslinked composites varied from 2.1 to 20.3 MPa for dry samples and from 0.4 to 16.6 MPa for wet samples. Main effects of each parameter on the measured property were calculated. The incorporation of mineralized bone fibers and an increase in PPF molecular weight resulted in higher compressive modulus and ultimate strength. Both mechanical properties also increased as the amount of benzoyl peroxide increased or the NVP amount decreased in the formulation. Sodium chloride had a dominating effect on the increase of mechanical properties in dry samples but showed little effects in wet samples. Demineralization of bone fibers led to a decrease in the compressive modulus and ultimate strength. Our results suggest that bone fibers are appropriate as structural enforcement components in PPF scaffolds. The desired orthopaedic PPF scaffold might be obtained by changing a variety of composite formulation parameters.
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Taylor, Oliver-Denzil S., Katherine E. Winters, Woodman W. Berry, Lucas A. Walshire, and Pamela G. Kinnebrew. "Near-surface soils: self-supported unconfined drained sand specimens." Canadian Geotechnical Journal 56, no. 3 (March 2019): 307–19. http://dx.doi.org/10.1139/cgj-2017-0261.
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Knowledge about soil behaviour in the near surface is fundamental to a broad range of military strategic research efforts. The prevailing mathematical representations of near-surface shear strength do not necessarily reflect the observed shear strengths. This paper presents an experimental procedure for testing self-supported, unconfined-drained specimens to investigate the shear strength of a poorly graded sand with the inferred unsaturated behaviour from typical effective stress expressions. The impact of soil suction is quantified from the soil–water characteristic curve obtained from a modified, unsaturated, one-dimensional oedometer device: Fredlund’s device. Seventy-seven unconfined tests illustrate that while individual or discrete states can be explained by effective stress relationships, those expressions do not accurately quantify the observed shear strength from one state to the next. Saturation failure is observed when the degree of saturation is between 70.5% and 76.5%, well below the assumed threshold. The results show that the dry shear resistance is a function of the initial density state, but as the degree of saturation increases, the shear resistance becomes independent of the initial density, and converges to the saturation failure. These findings expose the limitations of effective stress expressions and suggest a revised nonlinear, three-dimensional, unconfined Mohr failure envelope based on an applied external stress.
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Bolborea, Bogdan, Sorin Dan, Claudiu Matei, Aurelian Gruin, Cornelia Baeră, and Ion Aurel Perianu. "Estimating the Concrete Compressive Strength by Using the Concrete Ultrasonic Pulse Velocity and Moduli of Elasticity." Advanced Materials Research 1164 (June 23, 2021): 77–86. http://dx.doi.org/10.4028/www.scientific.net/amr.1164.77.
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Developing a non-destructive method which delivers fast, accurate and non-invasive results regarding the concrete compressive strength, is an important issue, currently investigated by many researchers all over the world. Different methodologies, like using the simple non-destructive testing (NDT) or the fusion of different techniques approach, were taken into consideration in order to find the optimal, most suitable method. The purpose of this paper is to present a new approach in this direction. The methodology consists in predicting the concrete compressive strength through ultrasonic testing, for non-destructive determination of the dynamic and static moduli of elasticity. One important, basic assumption of the proposed methodology considers values provided by technical literature for concrete dynamic Poisson’s coefficient. The air-dry density was experimentally determined on concrete cores. The dynamic modulus of elasticity was also experimentally determined by using the ultrasonic pulse velocity (UPV) method on concrete cores. Further on, the static modulus of elasticity and the concrete compressive strength can be mathematically calculated, by using the previously mentioned parameters. The experimental procedures were performed on concrete specimens, namely concrete cores extracted from the raft foundation of a multistorey building; initially they were subjected to the specific NDT, namely ultrasonic testing, and the validation of the results and the proposed methodology derives from the destructive testing of the specimens. The destructive testing is generally recognized as the most trustable method. The precision of the proposed method, established with respect to the destructive testing, revealed a high level of confidence, exceeding 90% (as mean value). It was noticed that even the cores with compressive strength outside of mean range interval (minimum and maximum values) presented high rate of precision, not influencing the overall result. The high rate of accuracy makes this method a suitable research background for further investigations, in order to establish a reliable NDT methodology which could substitute the very invasive and less convenient, destructive method.
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Mavroulidou, M., and S. Awoliyi. "A study on the potential use of paper sludge ash in concrete with glass aggregate." Waste Management & Research: The Journal for a Sustainable Circular Economy 36, no. 11 (October 5, 2018): 1061–65. http://dx.doi.org/10.1177/0734242x18801196.
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This short communication focuses on the potential use of paper sludge ash, a waste product of the paper making industry, as an innovative binder partially replacing cement in concrete with glass aggregate. After preliminary testing using binary or ternary CEM-II mixes with paper sludge ash/pulverised fly ash, a suitable mix for concrete with glass aggregate was identified. Concrete mixes with partial or full natural sand replacement by waste glass aggregate were then produced and showed appropriate strengths and overall similar or better water absorption characteristics than control mixes with natural aggregates, without manifest alkali-silica reaction problems. This shows potential for applications in precast dry mix concrete units based on the required strengths that were achieved.
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Bochare, Rewa, Monika Dagliya, Bindiya Sharma, and Faique Shaikh. "Experimental Investigation on Waste Paper-pulp Infused Cement Mortar." IOP Conference Series: Earth and Environmental Science 1130, no. 1 (January 1, 2023): 012006. http://dx.doi.org/10.1088/1755-1315/1130/1/012006.
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Abstract A huge amount of newspaper waste is generated in an average Indian household on a daily basis. The ideology behind this study is to amalgamate this paper waste into construction materials. This manuscript is a preliminary initiative for the same motive and explores the feasibility of mixing waste paper pulp into cement mortar for further adopting the practice on construction sites. Different ratios of cement, standard sand and crushed paper pulp (soaked for 72 hours) were administered to cast cement mortar cubes and the same were tested for compressive strength in a compression testing machine. The several trial mixes, partially replacing sand in mortar making were attempted to study the behavior of cement mortar while infused with waste paper pulp. The strength of these cubes were compared to standard cement mortar cubes cast using one part cement and 3 parts of standard sand. The trial ratios of cement, sand and paper pulp were 1:0.5:0.5; 1:0.75:0.25 and 1:0.25:0.75 respectively. Both 7 days as well as 28 days strength was determined. It was found that one part cement, half part standard sand and half a part of waste paper pulp was the most optimum combination yielding satisfactory strength of cement mortar cubes. The compressive strength of standard cube was 7.2 MPa and the same for 1:0.5:0.5 was 6.6 MPa. Thus waste paper pulp infused cement mortar may be used for brickwork and other trivial lean cement members in construction. The purpose of the study is to address two major underlying challenges in modern day construction projects, first being the dearth of river sand availability and secondly the disposal of waste paper which ultimately ends up in landfills subsequently polluting the environment.
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Ammar Anwar, Hamza Tariq, Shaheryar Adil, and Muhammad Ahsan Iftikhar. "Effect of curing techniques on compressive strength of concrete." World Journal of Advanced Research and Reviews 16, no. 3 (December 30, 2022): 694–710. http://dx.doi.org/10.30574/wjarr.2022.16.3.1379.
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This paper presented the findings of an experimental investigation into how common Portland cement concrete develops its compressive strength in a simple setting, such as Lahore, Pakistan. Ten concrete cube specimens of mix 1:1.5:3 was prepared with water-cement ratio of 0.5 for each of the four curing techniques (air curing, water-submerged curing, polythene curing, curing by boiling) until testing ages of 3, 7, 14, 21 and 28 days when their compressive strengths were determined. The findings demonstrated that concrete specimens produced using the water-submergence technique of curing had the maximum 28-day compressive strength of 41.42MPa. The findings indicate avoiding boiling as a curing process and restricting the use of other curing techniques to a 28-day timeframe. It was determined that there is a positive link between concrete specimen curing, curing duration, and compressive strength. This study also offers details on the significance of curing and numerous different methods for carrying out the procedure on the spot.
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Samal, Priyaranjan, Pandu R. Vundavilli, Arabinda Meher, and Manas Mohan Mahapatra. "Influence of TiC on dry sliding wear and mechanical properties of in situ synthesized AA5052 metal matrix composites." Journal of Composite Materials 53, no. 28-30 (June 18, 2019): 4323–36. http://dx.doi.org/10.1177/0021998319857124.
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In this paper, aluminium metal matrix composites were synthesized through in situ process in which aluminium alloy 5052 (AA5052) and titanium carbide were used as matrix and reinforcement materials, respectively. The microstructural characterization and formation of stable TiC phases were analyzed with the help of field emission scanning electron microscope, X-ray diffraction analysis, respectively. The 9% TiC-reinforced MMCs had shown a considerable improvement, i.e. 32% increase in hardness, 78% in ultimate tensile strength and 116% increase in yield strength when compared with the base alloy. The tensile fracture of the specimens shows dimples, voids, cracks, and ridges indicating the brittle nature. Further, the dry sliding wear properties of the composites were studied with the help of a pin-on-disc wear testing machine. The composite with 9% TiC exhibited a decrease in volumetric wear loss by 24% when compared with the base alloy at a load of 30 N. With increase in the TiC content and applied load, the COF values decreased linearly for the composites. The 9% TiC-reinforced composites show an abrasive mode of wear mechanism as a result of formation of deep grooves with no plastic deformation. With the improvement obtained in the wear properties, this metal matrix composite can be considered as a replacement for the conventional brake disc material used in the automobile industry.
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Memon, Bashir Ahmed, Mahboob Oad, Abdul Hafeez Buller, Sajjad Ahmed Shar, Abdul Salam Buller, and Fahad-u.-Rehman Abro. "Effect of Mould Size on Compressive Strength of Green Concrete Cubes." Civil Engineering Journal 5, no. 5 (May 21, 2019): 1181–88. http://dx.doi.org/10.28991/cej-2019-03091322.
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This paper is aimed to evaluate the effect of mould size on compressive strength of concrete cubes made with recyclable concrete aggregates. Natural coarse aggregates were replaced with 50% recycled aggregates from old demolished concrete. Five different mould sizes were used to cast 420 concrete cubes using 1:2:4 mix and 0.55 water/cement ratio. In each size equal number of cubes was cured for 3, 7, 14 and 28-day. After curing, weight of cubes was determined followed by testing for compressive strength in universal load testing machine with gradually increasing load. From the obtained results the strength correction coefficients were computed keeping 28-day cured standard size cubes as control specimens. Also, numerical expression based on regression analysis was developed to predict the compressive strength using weight of cube, area of mould and curing age as input parameter. The numerical equation predicts the compressive strength very well with maximum of 10.86% error with respect to experimental results.
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Smolinsky, Lawrence, Brian D. Marx, Gestur Olafsson, and Yanxia A. Ma. "Computer-Based and Paper-and-Pencil Tests: A Study in Calculus for STEM Majors." Journal of Educational Computing Research 58, no. 7 (June 8, 2020): 1256–78. http://dx.doi.org/10.1177/0735633120930235.
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Computer-based testing is an expanding use of technology offering advantages to teachers and students. We studied Calculus II classes for science, technology, engineering, and mathematics majors using different testing modes. Three sections with 324 students employed: paper-and-pencil testing, computer-based testing, and both. Computer tests gave immediate feedback and allowed multiple submissions and pooling. Paper-and-pencil tests (PPTs) required work and explanation allowing inspection of high cognitive demand tasks. Each test mode used the strength of its method. Students were given the same lecture by the same instructor on the same day and the same homework assignments and due dates. The design is quasi-experimental, but students were not aware of the testing mode at registration. Two basic questions examined were as follows: (a) Do paper-and-pencil and computer-based tests (CBTs) measure knowledge and skill in science, technology, engineering, and mathematics Calculus II in a consistent manner? (b) How does the knowledge and skill gained by students in a fully computer-based Calculus II class compare to students in a class requiring pencil-and-paper tests and hence some paper-and-pencil work. These results indicate that CBTs are as consistent with PPTs as CBTs are with themselves. Results are also consistent with classes using PPTs having slightly better outcomes than fully computer-based classes using only computer assessments.
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Quayson, Jeriscot H., and Zakari Mustapha. "IMPACT OF COARSE AGGREGATE ON COMPRESSIVE STRENGTH OF CONCRETE." Built Environment Journal 16, no. 1 (January 31, 2019): 52. http://dx.doi.org/10.24191/bej.v16i1.9674.
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Over one-third of the volume of concrete is occupied by coarse aggregate and any changes in coarse aggregate type can affect its strength and fracture properties. The paper examined the impact of coarse aggregates on compressive strength of concrete. Slump and compaction factor tests were conducted on the mixture of quartzite and crushed granite course aggregates, and quarry dust (fine aggregate). Nominal mix (1:2:3) was adopted and mix compositions were calculated by absolute weight method. Twelve (12) cubes (150x150mm) of each type of coarse aggregate were cast for 7, 14, 21, and 28 days to determine their compressive strengths. Quartzite was found to have the highest average compressive strength of 24.48N/mm2 with an average density of 2160kg/m3 , while compressive strength of crushed granite was 22.01N/mm2 with an average density of 2300kg/m3 on the 28 day of testing. Concrete made from granite had the highest workability, while concrete made from quartzite aggregate had the highest compressive strength. Densities and compressive strengths of the individual aggregates accounted for the variation in strengths of the concrete, due to differences in properties and strengths. In conclusion, the effect of any type of coarse aggregate on the compressive strength of concrete will be known and also enable contractors to determine the type of aggregate to be selected for a particular work.
Keywords: Compaction factor test; slump test; strength; workability.
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Degouet, Cédric, Blaise Nsom, Eric Lolive, and André Grohens. "Physical and Mechanical Characterization of Soya, Colza and Rye Seeds." Applied Rheology 17, no. 3 (June 1, 2007): 36546–1. http://dx.doi.org/10.1515/arh-2007-0010.
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Abstract This paper presents a characterization of the following dry granular materials: soya, colza and rye seeds. The physical properties of the grains and the materials are useful for characterizing the materials’ behaviour during flow, while the external conditions (consolidation) determine storage and handling conditions. The physical properties of the grains (specific densities) and of the materials as a whole (compacity or porosity, and critical angles) were measured. The flow functions were determined by modified shear box testing. Then the internal friction angles and the flowability index for each granular material were obtained. Indeed, the behaviour of a flowing granular material results from these two groups of factors and is characterized by the flowability, which is the ratio of highest consolidation stress and unconfined yield strength. In practice, the flowability index is used to classify materials, so that the larger the flowability index, the smaller the bulk solids strength will be in relation to the consolidation stress, and therefore the higher the flowability of the bulk solid.
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Otcovská, Tereza, Barbora Mužíková, and Pavel Padevět. "DRYING CHARACTERISTIC OF RAMMED EARTH WITH ILLITIC-KAOLINITIC CLAY CONTENT." Acta Polytechnica CTU Proceedings 13 (November 13, 2017): 89. http://dx.doi.org/10.14311/app.2017.13.0089.
Full textAbstract:
Clay is a traditional construction material which has got to background with introduction of modern materials to building practice. There is no proper material available for clay constructions design due to lack of proper examination of its mechanical properties. This paper focuses on drying rate of rammed earth. Drying is a primary way in which clay gets its strength. It is thus essential to know a duration needed to a construction to get dry. After pass of this time the maximum strength is attained and it is possible to load a construction. Properties of unburned clay are dependent on clay mix composition. In this contribution two sets of testing bodies with different composition are presented. As a bonding agent an illitic-kaolinite clay was used. It was presupposed that amount of used clay in clay mixture has major influence on the speed of drying and a final equilibrium moisture content. This presumption was disproved.