Journal articles: 'Physical-mechanical properties of AAM'

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Islam, MS, MG Aziz, MG Mortuza, and MA Rahman. "Profiling of Physical and Chemical Properties of Mango at Different Ripening Stages." Journal of Environmental Science and Natural Resources 9, no. 2 (April 14, 2017): 121–26. http://dx.doi.org/10.3329/jesnr.v9i2.32181.

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The experiments were carried out to assess the quality of mango at different ripening stages. The two factor experiment was laid out in completely randomized design (CRD) with three replications. The experiment comprised four varieties, viz., V1: BAU Aam-1, V2: BAU Aam-6, V3: BAU Aam-7, V4: BAU Aam-8 and five ripening stages. Among the attributes total weight loss, dry matter content, total soluble solids (TSS), sugar content (total, reducing and non-reducing), disease incidence increased, while the moisture, vitamin C contents and titratable acidity decreased with the increase in duration of storage. Among the four varieties, BAU Aam-6 showed better results in relation to the most of the characters examined. Ripening stage-5 of mango fruit was observed to be the best among the five ripening stages in relation to the most of the chemical characters examined. Finally, it can be concluded that the results of this experiment will be useful with particular reference to quality control, preparation for transportation and marketing, and will also be beneficial for both the growers and consumers.J. Environ. Sci. & Natural Resources, 9(2): 121-126 2016

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Gong, Jianqing, and Zhigang Qu. "Mechanical Properties and Drying Shrinkage Investigation of Alkali-Activated Mortar Using Waste Glass Powder." Advances in Civil Engineering 2020 (June 13, 2020): 1–13. http://dx.doi.org/10.1155/2020/8892474.

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Alkali-activated mortar (AAM) is one of the products of waste glass recycling that exhibits promising potential for wide engineering applications such as the construction industry. In this study, recycled waste glass powder-based additives, namely, Silica Fume (SF) and Nano-SiO2 (NS), were investigated for their potential to enhance the mechanical properties (strength) and drying-shrinkage resistance of AAM. The results indicated that 5.0% and 1.5% were the optimum SF and NS dosages, respectively, for optimizing AAM performance in terms of the compressive strength, flexural strength, and drying-shrinkage resistance. A prediction model, based on backpropagation (BP) neural network analysis, was also satisfactorily formulated and preliminarily validated for predicting the drying shrinkage of AAM containing SF or NS.

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Zhu, Xiu Fang, Ming Yang, Hong Xia Zhang, and Yu Jing Nie. "The Synthesis and Characteristic Properties of Poly (AAc-Co-AAm)." Advanced Materials Research 213 (February 2011): 534–38. http://dx.doi.org/10.4028/www.scientific.net/amr.213.534.

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The copolymers of 10% acrylic acid (AAc) and 90% acryl amide (AAm) were synthesized by free radical polymerization with 5% ethylene glycol dimethacrylate (EGDMA) as a crosslinker. The basic physical feature such as density, fixed charge density, average molecular weight, equilibrium water contentment and crosslink density were studied. In this investigation, the equilibrium and kinetic experiments were performed under three different ionic strengths, the equilibrium behavior of the hydrogels was characterized by varying the designed stimulus and by measuring the weight of hydrogel disc using a high accuracy balance. The ionic strength of the solution was adjusted with NaCl and the buffer solution was phosphoric acid. Potentiometric titration was performed to investigate the quantity of dissociated H+. Last, diffusion coefficients of aqueous sodium chloride in water swollen cross-linked poly (AAc-co-AAm) membranes were studied. A self-planned cell was used for the measurement of NaCl diffusion coefficients.

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Huang, Shu, Zhan Zhao, Chuang Feng, Edwin Mayes, and Jie Yang. "Nanocellulose reinforced P(AAm-co-AAc) hydrogels with improved mechanical properties and biocompatibility." Composites Part A: Applied Science and Manufacturing 112 (September 2018): 395–404. http://dx.doi.org/10.1016/j.compositesa.2018.06.028.

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Mierzwiński, Dariusz, Janusz Walter, and Piotr Olkiewicz. "The influence of alkaline activator concentration on the apparent activation energy of alkali-activated materials." MATEC Web of Conferences 322 (2020): 01008. http://dx.doi.org/10.1051/matecconf/202032201008.

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The aim of this article is to analyse the changes of apparent activation energy (Ea) of alkali-activated materials (AAM) at temperatures up to 100°C. Apparent activation energy (Ea) refers to the minimum amount of energy is required for the occurrence of reaction. The existing AAM research is based on assumptions about Portland cement (OPC). A number of studies have been conducted on the development of concrete strength depending on, inter alia, the duration of seasoning and the liquid to solid ratio (L/S). Based on the apparent activation energy and taking into account the effect of time and temperature at the same time, the physical and mechanical properties of OPC can also be predicted. The influence of the activator on the solidification process should also be taken into account for alkali-activated materials. This article shows the effect of changes in the concentration of the alkaline solution used in the AAM process on activation energy. The synthesized AAM material uses a solution based on water glass, sodium hydroxide, sand and volatile ash from the ‘Skawina’ coal-fired power plant (located in Skawina, Lesser Poland). The chemical composition of the material used is classified as class F ash. The concentration of the alkaline solution was 8M, 10M, 12M and 14M. The described research method was based on the use of thermistors with a negative temperature factor. It enabled prediction of the physical and mechanical properties of the materials tested. The results clearly indicate that this method can be used to determine the activation energy of the AAM. However, when determining apparent activation energy (Ea), the time and activation temperature of the binding processes of these types of materials should be taken into consideration.

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Choi, Sung, Gum-Sung Ryu, Kyeong-Taek Koh, Gi-Hong An, and Hyeong-Yeol Kim. "Experimental Study on the Shrinkage Behavior and Mechanical Properties of AAM Mortar Mixed with CSA Expansive Additive." Materials 12, no. 20 (October 11, 2019): 3312. http://dx.doi.org/10.3390/ma12203312.

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In this study, a calcium sulfoaluminate-based expansive additive (0%, 2.5%, 5.0%, and 7.5% by the mass of the binder) was added to compensate for the shrinkage of alkali-activated material (AAM) mortar. Modulus of elasticity curves based on the ACI 209 model were derived for the AAM mortar mixed with the additive by measuring the compressive strength and modulus of elasticity. Moreover, autogenous shrinkage and total shrinkage were measured for 150 days, and drying shrinkage was calculated by excluding autogenous shrinkage from total shrinkage. For the autogenous and drying shrinkage of AAM mortar, shrinkage curves by age were obtained by deriving material constants using the exponential function model. Finally, shrinkage stress was calculated using the modulus of elasticity of the AAM mortar and the curves obtained using the shrinkage model. The results showed that the calcium sulfoaluminate-based expansive additive had an excellent compensation effect on the drying shrinkage of AAM mortar, but the effect was observed only at early ages when the modulus of elasticity was low. From a long-term perspective, the shrinkage compensation effect was low when the modulus of elasticity was high, and thus, shrinkage stress could not be reduced.

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Adrus, Nadia, Nur Farizah Ayub, Nurul Atika Mohd Amer, and Jamarosliza Jamaluddin. "Mechanical Properties of the ‘Stretchable’ Polyacrylamide-Gelatin Double Network Hydrogel." Applied Mechanics and Materials 695 (November 2014): 328–31. http://dx.doi.org/10.4028/www.scientific.net/amm.695.328.

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Double network (DN) hydrogels have drawn considerable attention as innovative materials possessing both high water content as well as improved mechanical properties. In this study, DN hydrogels were formed from a combination of two hydrogel networks. The first network composed of acrylamide (AAm) andN’,N’-methylenebisacrylamide (MBAAm). AAm and MBAAm were covalently crosslinked via photopolymerization simultaneously with/without the presence of the second network pre-gel mixture; physically crosslinked gelatin-calcium carbonate (GCa). The mechanical properties characterization of the hydrogels revealed that tensile strength, Young’s modulus and elongation at break increased with the increasing amount of second network component; i.e. GCa. These data could confirmed that the polyacrylamide (PAAm)-GCa DN hydrogels possessed ‘stretchability’ character. Overall, PAAm-GCa DN hydrogels had shown better mechanical strength than the PAAm single network hydrogels. We foreseen that DN hydrogels are highly potential to be developed as artificial muscles.

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Faridmehr, Iman, Ghasan Fahim Huseien, and Mohammad Hajmohammadian Baghban. "Evaluation of Mechanical and Environmental Properties of Engineered Alkali-Activated Green Mortar." Materials 13, no. 18 (September 15, 2020): 4098. http://dx.doi.org/10.3390/ma13184098.

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Currently, alkali-activated binders using industrial wastes are considered an environmentally friendly alternative to ordinary Portland cement (OPC), which contributes to addressing the high levels of carbon dioxide (CO2) emissions and enlarging embodied energy (EE). Concretes produced from industrial wastes have shown promising environmentally-friendly features with appropriate strength and durability. From this perspective, the compressive strength (CS), CO2 emissions, and EE of four industrial powder waste materials, including fly ash (FA), palm oil fly ash (POFA), waste ceramic powder (WCP), and granulated blast-furnace slag (GBFS), were investigated as replacements for OPC. Forty-two engineered alkali-activated mix (AAM) designs with different percentages of the above-mentioned waste materials were experimentally investigated to evaluate the effect of each binder mass percentage on 28-day CS. Additionally, the effects of each industrial powder waste material on SiO2, CaO, and Al2O3 contents were investigated. The results confirm that adding FA to the samples caused a reduction of less than 26% in CS, whereas the replacement of GBFS by different levels of POFA significantly affected the compressive strength of specimens. The results also show that the AAM designs with a high volume FA provided the lowest EE and CO2 emission levels compared to other mix designs. Empirical equations were also proposed to estimate the CS, CO2 emissions, and EE of AAM designs according to their binder mass compositions.

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Liu, Li, Guangchao Lv, Xiuyan Ren, Xinhe Li, Te Wang, Jingwen Dong, Zeyu Wang, and Guangfeng Wu. "Effect of size of latex particles on the mechanical properties of hydrogels reinforced by latex particles." RSC Advances 9, no. 26 (2019): 14701–7. http://dx.doi.org/10.1039/c9ra01688k.

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Herein, cationic latex particles (CL) of different particle sizes were introduced as a cross-linking center to enhance the mechanical properties of the hydrophobically-associated hydrogels (P(AAm-co-HMA)-CL).

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Costa, Juliana O., Paulo H. R. Borges, Flávio A. dos Santos, Augusto Cesar S. Bezerra, Johan Blom, and Wim Van den bergh. "The Effect of Reclaimed Asphalt Pavement (RAP) Aggregates on the Reaction, Mechanical Properties and Microstructure of Alkali-Activated Slag." CivilEng 2, no. 3 (September 4, 2021): 794–810. http://dx.doi.org/10.3390/civileng2030043.

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Reclaimed asphalt pavement (RAP) is a recyclable aggregate produced during the demolition of old flexible pavements and consists of natural aggregates (NA) coated with aged bitumen. The detrimental effect caused by the bitumen coating on strength and porosity has limited the use of RAP on traditional cementitious systems. This study investigates the potential use of fine RAP to substitute NA in the production of alkali-activated slag mortars (AAM). The effect of different activator dosages was assessed, i.e., either 4% or 6% Na2O (wt. slag) combined with a modulus of silica equal to 0, 0.5 and 1.0. The characterisation of 100% RAP-AAM consisted of hydration kinetics (Isothermal Calorimetry), pore size distribution (Mercury Intrusion Porosimetry), mechanical performance (Compressive and Flexural strength), and microstructure analysis (Scanning Electron Microscopy and Confocal Laser Scanning Microscopy). The results show that RAP aggregates do not compromise the reaction of the matrices; however, it causes a significant strength loss (compressive strength of RAP-mortars 54% lower than reference NA-mortar at 28 days). The higher porosity at the interface transition zone of RAP-AAM is the main responsible for the lower strength performance. Increasing silicate dosages improves alkaline activation, but it has little impact on the adhesion between aggregate and bitumen. Despite the poorer mechanical performance, 100% RAP-AAM still yields enough strength to promote this recycled material in engineering applications.

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Zhu, Xiu Fang, Ming Yang, Hong Xia Zhang, and Yu Jing Nie. "The Mechanical Feature and Dependence of the pH-Sensitive Hydrogel." Advanced Materials Research 213 (February 2011): 479–82. http://dx.doi.org/10.4028/www.scientific.net/amr.213.479.

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Tensile tests were conducted on poly (AAc-co-AAm) hydrogel sensitive to variations in environmental pH and ionic strength. Mechanical properties (Young’s modulus) were determined at different levels of swelling equilibrium. The results show that there are great shift in the modulus number between the swollen and unswollen states, corresponding to the maximum, the Young’s modulus data in the pH7 buffers is a decrease of 80%. The Poisson’s ratio of the samples tested in the pH2 with 1.0M ionic strength solution is nearly 0.5, which implying its incompressibility. Analyzing its inner structure, the reason may be the high polymer chains entangled highly, they can resist the deformation. The further investigations of SEM micrographs prove our suggestions about the microstructure change.

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Nguyen, Hoc Thang, Van Phuc Nguyen, and Quang Minh Do. "Effects of Curing Time to Engineering Properties of Alkaline Activated Materials Synthesized from Thu Duc Water Plant Waste Sludge, Fly Ash, and Geopolymer Aggregate." Materials Science Forum 1029 (May 2021): 111–17. http://dx.doi.org/10.4028/www.scientific.net/msf.1029.111.

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Alkaline activated materials (AAM) are products of the reactions among activity oxides in high alkaline condition. AAM has many outstanding properties compared to other groups of similar materials. They are applied in many different fields such as construction materials, thermal insulation materials, refractory materials, catalytic materials, and adsorbents in environmental treatment. More importantly, AAMs are fabricated from raw materials of industrial solid waste such as fly ash, bottom ash, rice husk ash, red sludge, water plant waste sludge, blast furnace slag, and others. There are different synthesis and curing methods used to produce AAM. This study used the waste sludge of Thu Duc water plant mixed with fly ash, sand, geopolymer aggregate in alkaline solution prepared from water glass solution and NaOH to fabricate AAM. AAM products were then tested for engineering properties known as compressive strength, volumetric weight, water absorption, pH value, water content, and softening coefficient during various curing times of 1, 3, 7, 28, and 90 days.

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Lv, Xuesen, Yao Qin, Zhaoxu Lin, Zhenkun Tian, and Xuemin Cui. "One-Part Plastic Formable Inorganic Coating Obtain from Alkali-Activated Slag /Starch(CMS) Hybrid Composites." Molecules 25, no. 4 (February 14, 2020): 844. http://dx.doi.org/10.3390/molecules25040844.

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Coating technology can be applied to decorate building constructions. Alkali-activated materials (AAM) are promising green and durable inorganic binders which show potential for development as innovative coating. In the paper, the possibility of using AAM composited with starch (CMS) as a novel plastic formable inorganic coating for decorating in building was investigated. The rheological properties, including plastic viscosity, yield stress, and thixotropy were considered to be critical properties to obtain the working requirements. Four different mixtures were systematically investigated to obtain the optimum formulation, and then were used to study their hardened properties, such as mechanical strengths (compressive, flexural, and adhesive strength), drying shrinkage, cracking behavior, and microstructure. Study results found that CMS could quickly and efficiently be hydrolyzed in an alkaline solution to produce organic plastic gel which filled in AAM paste, leading to the significant improvement of coating consistency, plastic viscosity, and thixotropy. The optimum coating composited with 15.40 wt% CMS shows a relatively stable rheological development, the setting time sufficient at higher than 4 h. Furthermore, CMS shows a significant positive effect on the cracking and shrinkage control due to padding effect and water retention of CMS, which results in no visible cracks on the coating surface. Although the mechanical strength development is relatively lower than that of plain AAM, its value, adhesive strength 2.11 MPa, compressive strength 55.09 MPa, and flexural strength 8.06 MPa highly meet the requirements of a relevant standard.

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Faridmehr, Iman, Moncef L. Nehdi, Mehdi Nikoo, Ghasan Fahim Huseien, and Togay Ozbakkaloglu. "Life-Cycle Assessment of Alkali-Activated Materials Incorporating Industrial Byproducts." Materials 14, no. 9 (May 5, 2021): 2401. http://dx.doi.org/10.3390/ma14092401.

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Eco-friendly and sustainable materials that are cost-effective, while having a reduced carbon footprint and energy consumption, are in great demand by the construction industry worldwide. Accordingly, alkali-activated materials (AAM) composed primarily of industrial byproducts have emerged as more desirable alternatives to ordinary Portland cement (OPC)-based concrete. Hence, this study investigates the cradle-to-gate life-cycle assessment (LCA) of ternary blended alkali-activated mortars made with industrial byproducts. Moreover, the embodied energy (EE), which represents an important parameter in cradle-to-gate life-cycle analysis, was investigated for 42 AAM mixtures. The boundary of the cradle-to-gate system was extended to include the mechanical and durability properties of AAMs on the basis of performance criteria. Using the experimental test database thus developed, an optimized artificial neural network (ANN) combined with the cuckoo optimization algorithm (COA) was developed to estimate the CO2 emissions and EE of AAMs. Considering the lack of systematic research on the cradle-to-gate LCA of AAMs in the literature, the results of this research provide new insights into the assessment of the environmental impact of AAM made with industrial byproducts. The final weight and bias values of the AAN model can be used to design AAM mixtures with targeted mechanical properties and CO2 emission considering desired amounts of industrial byproduct utilization in the mixture.

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Zhu, Xiu Fang, Ming Yang, Hong Xia Zhang, and Yu Jing Nie. "The Synthesis and Feature Rearch on the Thermosensitive Hydrogels (NIPA-co-AAm)." Materials Science Forum 704-705 (December 2011): 913–17. http://dx.doi.org/10.4028/www.scientific.net/msf.704-705.913.

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The polymer was prepared by the radical copolymerization. Tensile tests were conducted on a N-isopropylacrylamide (NIPA)-acrylamide (AAm) comonomer gel sensitive to variations in environmental temperature. and salinity Mechanical properties (Young’s modulus) were determined at different levels of swelling equilibrium. Shifts in the mechanical properties were observed between samples tested in the swollen and unswollen states. Additional tests were conducted to determine the effect of salinity on the LCST. Increasing the salinity from 0M to 1.0M resulted in a decrease in LCST (55centigrade to 28centigrade).It is found that adjustment of the salinity of the environment solution is an effective method of controlling the LCST of the gel. Keywords: Salinity, hydrogels, mechanical properties

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Bumanis, Girts, Diana Bajare, and Janis Locs. "The Effect of Activator on the Properties of Low-Calcium Alkali-Activated Mortars." Key Engineering Materials 604 (March 2014): 169–72. http://dx.doi.org/10.4028/www.scientific.net/kem.604.169.

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Properties of the low-calcium alkali-activated materials (AAMs) made from the metakaolin, waste glass and sand were tested in this research. Specimens with dimensions 40x40x160mm were prepared. The correlation between development of microstructure and concentration of NaOH solution used for preparing of the AAMs was observed. Structure investigation with SEM and FTIR was performed to describe the formation of microstructure in low-calcium AAMs. The research results aimed that the improvement of physical and mechanical properties of the AAMs with increasing the activator’s concentration from 2 to 10 mol/kg H2O were in concordance with the structure development of AAM. The 28 days old AAMs with a compressive strength up to 31MPa and water absorption lower than 2% were obtained by using activator with concentration 10 mol/kg H2O.

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Samadi, Mostafa, Kwok Wei Shah, Ghasan Fahim Huseien, and Nor Hasanah Abdul Shukor Lim. "Influence of Glass Silica Waste Nano Powder on the Mechanical and Microstructure Properties of Alkali-Activated Mortars." Nanomaterials 10, no. 2 (February 14, 2020): 324. http://dx.doi.org/10.3390/nano10020324.

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The recycling of millions of tons of glass bottle waste produced each year is far from optimal. In the present work, ground blast furnace slag (GBFS) was substituted in fly ash-based alkali-activated mortars (AAMs) for the purpose of preparing glass bottle waste nano-powder (BGWNP). The AAMs mixed with BGWNP were subsequently subjected to assessment in terms of their energy consumption, economic viability, and mechanical and chemical qualities. Besides affording AAMs better mechanical qualities and making them more durable, waste recycling was also observed to diminish the emissions of carbon dioxide. A more than 6% decrease in carbon dioxide emissions, an over 16% increase in compressive strength, better durability and lower water absorption were demonstrated by AAM consisting of 5% BGWNP as a GBFS substitute. By contrast, lower strength was exhibited by AAM comprising 10% BGWNP. The conclusion reached was that the AAMs produced with BGWNP attenuated the effects of global warming and thus were environmentally advantageous. This could mean that glass waste, inadequate for reuse in glass manufacturing, could be given a second life rather than being disposed of in landfills, which is significant as concrete remains the most commonplace synthetic material throughout the world.

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Zhen, Yanzhong, Jie Wang, Feng Fu, Wenhao Fu, and Yucang Liang. "The Novel Z-Scheme Ternary-Component Ag/AgI/α-MoO3 Catalyst with Excellent Visible-Light Photocatalytic Oxidative Desulfurization Performance for Model Fuel." Nanomaterials 9, no. 7 (July 23, 2019): 1054. http://dx.doi.org/10.3390/nano9071054.

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The novel ternary-component Ag/AgI/α-MoO3 (AAM) photocatalyst was successfully fabricated by a facile hydrothermal method combined with a charge-induced physical adsorption and photo-reduced deposition technique. X-ray diffraction, scanning/transmission electron microscope, X-ray photoelectron, UV-vis diffuse reflectance, photoluminescence and electrochemical impedance spectroscopy were employed to characterize the composition, morphology, light-harvesting properties and charge transfer character of the as-synthesized catalysts. The ternary-component AAM heterojunctions exhibited an excellent visible-light photocatalytic oxidative desulfurization activity, in which the AAM-35 (35 represents weight percent of AgI in AAM sample) possessed the highest photocatalytic activity of the conversion of 97.5% in 2 h. On the basis of band structure analysis, radical trapping experiments and electron spin resonance (ESR) spectra results, two different catalytic mechanisms were suggested to elucidate how the photogenerated electron-hole pairs can be effectively separated for the enhancement of photocatalytic performance for dual composites AM-35 and ternary composites AAM-35 during the photocatalytic oxidative desulfurization (PODS) of thiophene. This investigation demonstrates that Z-scheme Ag/AgI/α-MoO3 will be a promising candidate material for refractory sulfur aromatic pollutant’s removal in fossil fuel.

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Mulijani, Sri, Erizal, Tun Tedja Irawadi, and Tyas Cipta Katresna. "Composite Copolymer Acrylamide/Bacterial Cellulose Hydrogel Synthesis and Characterization by the Application of Gamma Irradiation." Advanced Materials Research 974 (June 2014): 91–96. http://dx.doi.org/10.4028/www.scientific.net/amr.974.91.

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Realizing the growing extraordinary interest in the development of polymer hydrogels, successful attempt has been made for synthesis of copolymer hydrogels from aqueous solution of acrylamide/bacterial cellulose (AAm/BC) with irradiation processing technology using Co-60 gamma source. The study envisaged to: (i) develop a novel high strength polymer nanocomposite hydrogels containing natural BC, and (ii) investigate chemical structure, morphology, and mechanical strength properties of the formed gels. The effectiveness of AAm/BC hydrogel for wound dressing application was also tested. Structure and properties of composite were investigated using Fourier Transform Infrared spectrophotometer (FTIR), Differential Scanning Calorimetry (DSC), and Atomic force microscopy (AFM). While investigating the influence of irradiation dose and concentration of acrylamide on gel content, swelling properties and thermal stability of copolymer hydrogel,maximum gel content of prepared hydrogel was obtained at the radiation dose of 40 kGy. Swelling ratio and equilibrium water content increased with increasing irradiation dose and concentration of acrylamide in feed solution. The water absorption of hydrogel increased with increased standing time in swelling medium. It was rapid up to 24 h and got slowed down thereafter. The water absorption also increased with increasing concentration of irradiation dose in the feed solution. The water absorption of copolymer hydrogel obtained at 40 kGy irradiation dose decreased from 1800 to 1400%. This type of diffusion of prepared hydrogel was found to be a non Fickian diffusion. The thermal stability of copolymer hydrogel prepared at the irradiation dose of 40 kGy increased with increasing amount of AAm in the feed solution. The mechanical behavior of composite hydrogels at optimum irradiation dose performed value of tensile and strain at 46.3MPa and 36.6%, respectively.

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Zong, Ruilong, Ji Zhou, Qi Li, Longtu Li, Weitian Wang, and Zhenghao Chen. "Linear and nonlinear optical properties of Ag nanorods/AAM composite films." Chemical Physics Letters 398, no. 1-3 (November 2004): 224–27. http://dx.doi.org/10.1016/j.cplett.2004.09.059.

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Kim, Yong-Rak, Dallas N. Little, and Injun Song. "Effect of Mineral Fillers on Fatigue Resistance and Fundamental Material Characteristics: Mechanistic Evaluation." Transportation Research Record: Journal of the Transportation Research Board 1832, no. 1 (January 2003): 1–8. http://dx.doi.org/10.3141/1832-01.

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Complex characteristics of fatigue behavior were evaluated on the basis of test results and their mechanical analyses. The dynamic shear rheometer was used to characterize fundamental linear viscoelastic properties of asphalt binders and mastics. Various dynamic mechanical tests using cylindrical sand–asphalt samples mixed with pure binders, mastics, or both were also performed to estimate viscoelastic characteristics and fatigue behavior. To assess the filler effect, two distinctly compositionally different asphalt binders, AAD-1 and AAM-1, and two fillers, limestone and hydrated lime, were selected. Test results were analyzed using viscoelastic theory, a fatigue prediction model based on continuum damage mechanics, and a rheological composite model. The role of fillers in fatigue resistance was quantified, and induced mechanisms due to filler addition were investigated. The effect of hydrated lime, which is highly binder specific, as a filler was further discussed by comparing test results from hydrated lime filler and test results from limestone filler.

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Mukhametgazy, N., I. Sh Gussenov, A. V. Shakhvorostov, and S. E. Kudaibergenov. "Salt tolerant acrylamide-based quenched polyampholytes for polymer flooding." Bulletin of the Karaganda University. "Chemistry" series 100, no. 4 (December 30, 2020): 119–27. http://dx.doi.org/10.31489/2020ch4/119-127.

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In our previous papers [1, 2] we considered the behavior of linear and crosslinked polyampholytes based on fully charged anionic monomer — 2-acrylamido-2-methyl-1-propanesulfonic acid sodium salt (AMPS) and cationic monomer — (3-acrylamidopropyl)trimethylammonium chloride (APTAC) in aqueous-salt solutions, swelling and mechanical properties. In the present paper we report the applicability of salt tolerant amphoter-ic terpolymers composed of AMPS, APTAC and acrylamide (AAm) in enhanced oil recovery (EOR). The amphoteric terpolymers of different compositions, particularly [AAm]:[AMPS]:[APTAC] = 50:25:25; 60:20:20; 70:15:15; 80:10:10 and 90:5:5 mol.% were prepared by free-radical polymerization, identified and their viscosifying ability with respect to reservoir saline water (salinity is 163 g⋅L-1) at 60 °C was tested. It was found that due to polyampholytic nature, the AAm-AMPS-APTAC terpolymers exhibited improved viscosifying behavior at high salinity water. As a result, the appropriate salt tolerant sample [AAm]:[AMPS]:[APTAC] = 80:10:10 mol.% was selected for polymer flooding experiments. Polymer flood-ing experiments on high permeable sand pack model demonstrated that only 0.5 % oil was recovered by am-photeric terpolymer. While injection of polyampholyte solution into preliminarily water flooded core sample resulted in the increase of oil recovery up to 4.8–5 %. These results show that under certain conditions the amphoteric terpolymers have a decent oil displacement ability.

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Prochon, Piotr, Zengfeng Zhao, Luc Courard, Tomasz Piotrowski, Frédéric Michel, and Andrzej Garbacz. "Influence of Activators on Mechanical Properties of Modified Fly Ash Based Geopolymer Mortars." Materials 13, no. 5 (February 25, 2020): 1033. http://dx.doi.org/10.3390/ma13051033.

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The aim of this work was to study the influence of the type of activator on the formulation of modified fly ash based geopolymer mortars. Geopolymer and alkali-activated materials (AAM) were made from fly ashes derived from coal and biomass combustion in thermal power plants. Basic activators (NaOH, CaO, and Na2SiO3) were mixed with fly ashes in order to develop binding properties other than those resulting from the use of Portland cement. The results showed that the mortars with 5 mol/dm3 of NaOH and 100 g of Na2SiO3 (N5-S22) gave a greater compressive strength than other mixes. The compressive strengths of analyzed fly ash mortars with activators N5-S22 and N5-C10 (5 mol/dm3 NaOH and 10% CaO) varied from 14.3 MPa to 5.9 MPa. The better properties of alkali-activated mortars with regular fly ash were influenced by a larger amount of amorphous silica and alumina phases. Scanning electron microscopy and calorimetry analysis provided a better understanding of the observed mechanisms.

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Kalia, Susheel, and B. S. Kaith. "Mechanical Properties of Phenolic Composites Reinforced with Flax-g-copolymers Prepared under Different Reaction Conditions - A Comparative Study." E-Journal of Chemistry 5, no. 1 (2008): 177–84. http://dx.doi.org/10.1155/2008/538397.

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Graft copolymers of methyl methacrylate (MMA) and its binary mixtures such as MMA + ethyl acrylate (EA), MMA + acrylonitrile (AN), MMA + acrylic acid (AA), MMA + vinyl acetate (VA), MMA + acrylamide (AAm) and MMA + styrene (Sty) with flax fiber have been prepared in air (IA) and under the influence of microwave radiations (MWR). Synthesized flax-g-copolymers under two different reaction conditions were used as reinforcing material in the preparation of phenol-formaldehyde composites. Mechanical properties such as wear resistance, modulus of rupture (MOR), modulus of elasticity (MOE) and stress at the limit of proportionality (SP) were measured and a comparative studied has been made. It has been found that composites reinforced with flax-g-copolymers-MWR showed better mechanical properties in comparison to composites reinforced with flax-g-copolymers-IA

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Cristelo, Nuno, Fernando Castro, Tiago Miranda, Zahra Abdollahnejad, and Ana Fernández-Jiménez. "Iron and Aluminium Production Wastes as Exclusive Components of Alkali Activated Binders—Towards a Sustainable Alternative." Sustainability 13, no. 17 (September 4, 2021): 9938. http://dx.doi.org/10.3390/su13179938.

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The sustainability of resources is becoming a worldwide concern, including construction and building materials, especially with the alarming increase rate in global population. Alternative solutions to ordinary Portland cement (OPC) as a concrete binder are being studied, namely the so-called alkali-activated cements (AAC). These are less harmful to the environment, as lower CO2 emissions are associated with their fabrication, and their mechanical properties can be similar to those of the OPC. The aim of developing alkali-activated materials (AAM) is the maximization of the incorporated recycled materials, which minimises the CO2 emissions and cost, while also achieving acceptable properties for construction applications. Therefore, various efforts are being made to produce sustainable construction materials based on different sources and raw materials. Recently, significant attention has been raised from the by-products of the steelmaking industry, mostly due to their widespread availability. In this paper, ladle slag (LS) resulting from steelmaking operations was studied as the main precursor to produce AAC, combined with phosphating bath sludge—or phosphate sludge (PS)—and aluminium anodising sludge (AS), two by-products of the surface treatment of metals, in replacement rates of 10 and 20 wt.%. The precursors were activated by two different alkaline solutions: a combination of commercial sodium hydroxide and sodium silicate (COM), and a disposed solution from the cleaning of aluminium extrusion steel dies (CLE). This study assesses the influence of these by-products from the steelmaking industry (PS, AS and CLE) on the performance of the alkali-activated LS, and specifically on its fresh and hardened state properties, including rheology, heat of hydration, compressive strength and microstructure and mineralogy (X-ray diffraction, scanning electron microscopy coupled with energy dispersive spectroscopy and Fourier transform infra-red. The results showed that the CLE had no negative impact on the strength of the AAM incorporating PS or/and AS, while increasing the strength of the LS alone by 2×. Additionally, regardless of the precursor combination, the use of a commercial activator (COM) led to more fluid pastes, compared with the CLE.

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Netzel, Daniel A. "Low Temperature Studies of Amorphous, Interfacial, and Crystalline Phases in Asphalts Using Solid-State 13C Nuclear Magnetic Resonance." Transportation Research Record: Journal of the Transportation Research Board 1638, no. 1 (January 1998): 23–30. http://dx.doi.org/10.3141/1638-03.

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The road performance behavior of an asphalt depends upon its susceptibility to changes in its rheological properties with time and temperature. One important fundamental molecular property of an asphalt, which dictates its temperature-dependent performance, is the nature of the molecular motions associated with the asphalt molecular components. Changes in the rotational motions of the methyl carbons and the segmental motions of the methylene carbons in the 1- to 10-kHz frequency range were studied (via changes in spin-spin dipolar-dephasing relaxation times) as a function of temperature for three Strategic Highway Research Program asphalts using carbon-13 dipolar-dephasing cross polarization with magic angle spinning nuclear magnetic resonance. The data indicate that the rotational motion of the terminal methyl carbons of n-alkanes in the amorphous phase is nearly independent of decreasing temperature until the glass-transition region is reached. Below the Tg, the rotational motion of the methyl carbons decreases slowly with decrease in temperature for asphalts AAA-1 and AAB-1. However, the methyl rotation in asphalt AAM-1 decreases more rapidly. The segmental motions of the methylene carbons in the mobile-amorphous phase for the different asphalts decrease rapidly with decreasing temperature from 20 to – 20°C. At temperatures below — 20°C, the segmental motions have essentially ceased. The slow, low-frequency motions of the methylene carbons in the inter-facial (rigid-amorphous) and crystalline phases were found to be independent of temperature above and below Tg. It is suggested that the methyl rotation and segmental motions of the methylene carbons in the amorphous phase extensively influence the low-temperature rheological properties of asphalts.

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Struhárová, Alena, Stanislav Unčík, Svetozár Balkovic, and Mária Hlavinková. "Influence of Fluidized Fly Ash on the Selected Physical-Mechanical Properties of the Autoclaved Aerated Concrete." Advanced Materials Research 899 (February 2014): 409–14. http://dx.doi.org/10.4028/www.scientific.net/amr.899.409.

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Fluidized fly ash has different physical and chemical properties compared to fly ash emerging from classic combustion. It contains amorphous phases resulting from a dehydration of clay minerals as well as unreacted sorbent of CaCO3, free CaO and anhydrite (CaSO4). Work targets the possibilities of production of an autoclaved aerated concrete (AAC) from fluidized fly ash, and its influence on particular physical-mechanical properties of autoclaved aerated concrete.

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Thongtha, Atthakorn, Somchai Maneewan, Chantana Punlek, and Yothin Ungkoon. "Application Using Sugar Sediment to Enhance Mechanical Properties of Autoclaved Aerated Concrete." Applied Mechanics and Materials 459 (October 2013): 664–68. http://dx.doi.org/10.4028/www.scientific.net/amm.459.664.

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The effect of fine sand replacement by the sugar sediment (0, 10, 15, 20, 25, 30, 35, 40, 45 and 50 weight %) on the physical and mechanical properties was studied in this work. The physical and mechanical properties of AAC with various contents of sugar sediment were focused on the density, the humidity, the water absorption, the open porosity volume, the compressive strength and the flexural strength. The average density, humidity, water absorption, volume of open porosity, compressive strength and flexural strength of all compositions had the value in the range of 0.57-0.61 g/cm3, 23.0-26.7 %, 0.38-0.40 g/cm3, 259-287 cm3, 4.4-5.9 N/mm2and 1.03-1.82 N/mm2, respectively. The maximum compressive strength and flexural strength were found from the AAC sample with the sugar sediment content of 30%, which were 5.9 N/mm2and 18.14 N/mm2. Moreover, these samples also exhibited the density (0.60 g/cm3), the humidity (23.6%), the water absorption (0.39 g/cm3) and the volume of open porosity (272 cm3) were claimed in quality class of 4. The specimens of AAC with the sugar sediment content of 0-40% were claimed in quality class of 4, which based on the Thai Industrial Standard 1505-1998.

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Gomaa, Eslam, Simon Sargon, Cedric Kashosi, Ahmed Gheni, and Mohamed A. ElGawady. "Mechanical Properties of High Early Strength Class C Fly Ash-Based Alkali Activated Concrete." Transportation Research Record: Journal of the Transportation Research Board 2674, no. 5 (May 2020): 430–43. http://dx.doi.org/10.1177/0361198120915892.

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This paper presents the mechanical properties of alkali activated concrete (AAC) cured at 70°C for 24 h. The AAC mixtures were synthesized using five class C fly ashes (FAs) having different chemical and physical properties. Sodium hydroxide (SS) and sodium silicate (SH) were used as the alkali activators in this study. A conventional concrete (CC) mixture, having a compressive strength of 34.5 MPa, was synthesized using ordinary Portland cement (OPC) mixture for comparison purposes. The slump, as well as the compressive, tensile splitting, and flexural strengths were investigated at different concrete ages up to 28 days. The results revealed that with increasing the calcium content in an FA used to synthesized AAC mixture, the slump value and the mechanical properties decreased. All AAC mixtures reached approximately 92% of their 28-day compressive strength after 1 day compared with only 29% in the case of CC. Therefore, AAC can be used in applications where rapid strength gain is required, such as urgent repair, precast industry, and so forth. The measured data was also used to develop a set of equations to accurately predict the splitting tensile and flexural strengths.

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Batista, Raquel P., Juliana O. Costa, Paulo H. R. Borges, Flávio A. Dos Santos, and Fernando S. Lameiras. "High-performance alkali-activated composites containing an iron-ore mine tailing as aggregate." MATEC Web of Conferences 274 (2019): 02004. http://dx.doi.org/10.1051/matecconf/201927402004.

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High-performance cementitious composites have been developed to overcome the brittleness of mortars and concretes, thus improving the deformation and toughness of these materials under flexion and tension. Poli Vinyl Alcohol (PVA) fibres are employed in the production of such “Engineered Cementitious Composites” - ECC; the PVA fibres have a loadcarrying capacity after the first crack (matrix failure), which changes the mechanical behaviour of the composites from brittle to ductile and significantly increases the ultimate strength. This deflection or strain-hardening behaviour is accompanied by a multiple cracking of the composites, which results from the design of a proper formulation, with correct amount of PVA fibres (usually 2% vol. fraction) and employment of a very fine sand (passing 0.6 mm). Recent developments in the area of ECC comprise the replacement of Portland cement (PC) matrices with alkali-activated materials (AAM). The idea is to produce composites with similar performance but with improved chemical durability and lower environmental impact. A more sustainable solution would consider the replacement of the fine sand with mine tailings in the production of ECC-AAM. Some tailings from the iron-ore mining activities in Brazil are significantly finer than those aggregates used for PC mortars and concretes; therefore, they cannot be employed in traditional PC-based materials. Nevertheless, those fine materials could replace the fine natural aggregate used in the production of ECC. This paper investigates the replacement of a natural quartz sand with an iron-rich mine tailing in PVA-reinforced AAM. Four composites were studied from a combination of two different matrices and 2 different aggregates. The matrices were obtained from the alkaline activation of metakaolin (MK) with sodium silicate (Na2SiO3) and sodium hydroxide (NaOH); silica fume (SF) was used to adjust their composition: SiO2 / Al2O3 molar ratio equal to 3.0 or 3.8. The aggregates used were either natural quartz (passing 0.6 mm) or tailings produced during the mining activities of iron ore in the state of Minas Gerais, Brazil. The mine tailing studied is much finer than the natural sand (passing 0.3 mm) but it was used as received in the production of ECC-AAM. The aggregate to binder ratio was kept constant (equal to 1.0 in mass) irrespective of the type of aggregate. All mortars were reinforced with 2% vol. of PVA fibres; extra water was added to the mixes to maintain the same consistency for the composites. The mechanical properties investigated are compressive strength, flexural strength and toughness. The apparent dry density of the mortars was also assessed. The preliminary results presented in this paper indicate that iron-rich tailings may be effectively used in the production of ECC-AAM; however, durability tests are still necessary.

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Traven, Katja, Mark Češnovar, and Vilma Ducman. "Particle size manipulation as an influential parameter in the development of mechanical properties in electric arc furnace slag-based AAM." Ceramics International 45, no. 17 (December 2019): 22632–41. http://dx.doi.org/10.1016/j.ceramint.2019.07.296.

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Singh, Baljit, and Lok Pal. "Sterculia crosslinked PVA and PVA-poly(AAm) hydrogel wound dressings for slow drug delivery: Mechanical, mucoadhesive, biocompatible and permeability properties." Journal of the Mechanical Behavior of Biomedical Materials 9 (May 2012): 9–21. http://dx.doi.org/10.1016/j.jmbbm.2012.01.021.

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Barabanova, Anna, Andrei Shibaev, Vyacheslav Molchanov, Olga Philippova, and Alexei Khokhlov. "Preparation of Magnetic Fluids Based on Associated Polymers." Advanced Materials Research 650 (January 2013): 314–19. http://dx.doi.org/10.4028/www.scientific.net/amr.650.314.

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This paper describes two methods of preparation of magnetic fluids based on associated polymers. The first method is ultrasonic (US) dispersing of magnetite microparticles (MP) in aqueous solutions of associated polymers such as hydrophobically modified polyacrylamides (HM PAAm) – terpolymers of acrylamide (AAm), sodium acrylate (SA) and N-dodecylacrylamide (DDAA). According to the second method the magnetic fluids were formed by addition of magnetic polymers, synthesized by means of a micellar copolymerization of AA, SA and DDAA in the presence of MP, into water. The investigation of the rheological properties has shown that magnetic fluids obtained can be reversibly transformed in physical gels in magnetic field (MF).

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Grigoryeva, O., A. Fainleib, J. Grenet, and J. M. Saiter. "Reactive Compatibilization of Recycled Polyethylenes and Scrap Rubber in Thermoplastic Elastomers: Chemical and Radiation-Chemical Approach." Rubber Chemistry and Technology 81, no. 5 (November 1, 2008): 737–52. http://dx.doi.org/10.5254/1.3548229.

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Abstract Reactive compatibilization of recycled low- or high-density polyethylenes (LDPE and HDPE, respectively) and ground tire rubber (GTR) via chemical interactions of pre-functionalized components in their blend interface has been carried out. Polyethylene component was functionalized with maleic anhydride (MAH); as well, the rubber component was modified via functionalization with MAH or acrylamide (AAm) using chemically or irradiation (γ-rays) induced grafting techniques. The grafting degree and molecular mass distribution of the functionalized polymers have been measured via FTIR and Size Exclusion Chromatography (SEC) analyses, respectively. Additional coupling agents such as p-phenylene diamine (PDA) and polyamide fiber were used for producing some thermoplastic elastomer (TPE). Thermoplastic elastomer materials based on synthesized reactive polyethylenes and GTR as well as ethylene-propylenediene monomer rubber (EPDM) were prepared by dynamic vulcanization of the rubber phase inside thermoplastic (polyethylene) matrix and their phase structure, and main properties have been studied using DSC, DMTA and mechanical testing. As a result, high performance thermoplastic elastomers based on functionalized polyethylene and ground rubber with improved mechanical properties have been developed.

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Lédl, Matěj, Lucie Galvánková, and Rostislav Drochytka. "Effect of Ammonium Ion Content in Fly Ash after Selective Non-Catalytic Reduction (SNCR) on Physical and Mechanical Properties of Autoclaved Aerated Concrete (AAC)." Solid State Phenomena 276 (June 2018): 148–53. http://dx.doi.org/10.4028/www.scientific.net/ssp.276.148.

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After introducing SNCR in coal combustion process in power plants, the valuable by-product such as fly ash remains contaminated with amount of ammonia in form of NH4HSO4, (NH4)2SO4 respectively, which became undesirable in AAC technology because the toxic ammonia is released in the air during the mixing process. This paper deals with the effect of varying ammonia content in fly ash after selective non-catalytic reduction (SNCR) on the physical-mechanical properties of the fly ash based autoclaved aerated concrete (AAC) with the main focus on determination of the impact of the various content of ammonium ion in fly ash on the initial consistency of fresh slurry, the residual content of ammonium ion in hardened aerated matrix and also the impact on the bulk density, compressive strength and tobermorite formation after hydrothermal treatment. Seven batches of AAC, made out of fly ash with rising content of ammonium ion from 0 ppm to 250 ppm, were tested and based on the results obtained it was found out that ammonia is released during the mixing process entirely and doesn‘t remain in AAC after autoclaving, moreover it doesn‘t affect the properties of both fresh slurry (no apparent foaming effect noticed) and thermally treated samples of AAC. Formation of tobermorite wasn’t negatively affected.

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Liu, Zhanqing, Yanling Luo, and Kaipu Zhang. "P(AAm-co-MAA) semi-IPN hybrid hydrogels in the presence of PANI and MWNTs-COOH: improved swelling behavior and mechanical properties." Journal of Biomaterials Science, Polymer Edition 19, no. 11 (January 2008): 1503–20. http://dx.doi.org/10.1163/156856208786140373.

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Janovák, László, János Varga, Lajos Kemény, and Imre Dékány. "The effect of surface modification of layer silicates on the thermoanalytical properties of poly(NIPAAm-co-AAm) based composite hydrogels." Journal of Thermal Analysis and Calorimetry 98, no. 2 (August 7, 2009): 485–93. http://dx.doi.org/10.1007/s10973-009-0311-1.

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Yousuf, Fatima, M. Talha Junaid, and Salah Altoubat. "Drying Shrinkage Performance of Ambient Cured Blended Alkali-Activated Concrete." Defect and Diffusion Forum 394 (August 2019): 109–14. http://dx.doi.org/10.4028/www.scientific.net/ddf.394.109.

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The environmental burden due to the production and use of Ordinary Portland Cement(OPC) has become significant in terms of resource use and atmospheric emissions. Alkali-activatedbinders have gained significant attention in recent years as a possible alternative to OPC. Concreteundergoes physical and chemical changes through its lifetime. These changes affect propertiesresulting in either increase or decrease of performance and serviceability. Concrete contracts due tothese changes leading to shrinkage. Shrinkage induces tensile stresses within the members, whichleads to a tendency of cracking, resulting in compromised durability. Shrinkage behavior analysis ofAlkali-Activated Concrete (AAC), without any external loading, is crucial to assess as there is limiteddata available. To further test for shrinkage under restraint conditions, mix development of AAC isnecessary. Mechanical properties and drying shrinkage potential of AAC are evaluated and comparedwith OPC concrete. Basic properties assessed to understand the performance of AAC are compressivestrength, splitting tensile strength and free drying shrinkage. Drying shrinkage test is performed as perASTM C157 for 90 days. Furthermore, the effect of different curing regimes (dry curing, three daysmoist curing, and seven days moist curing) on the mechanical properties and shrinkage is evaluated.The results show that drying shrinkage of AAC exhibit similar behavior to that of OPC concrete whilehaving better early-age strength under moist curing regimes.

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Flora, Harpaul S., Bijan Talei-Faz, Leslie Ansdell, Edmund J. Chaloner, Aaron Sweeny, Anthony Grass, and Mohan Adiseshiah. "Aneurysm Wall Stress and Tendency to Rupture are Features of Physical Wall Properties: An Experimental Study." Journal of Endovascular Therapy 9, no. 5 (October 2002): 665–75. http://dx.doi.org/10.1177/152660280200900518.

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Purpose: To use bench top techniques to examine the biophysical phenomena affecting the risk of abdominal aortic aneurysm (AAA) rupture relative to the physical properties of the aneurysm sac. Methods: Three latex AAAs with different wall elasticities were tested in a validated pulsatile flow model (PFM). Strain gauges were wired to each AAA model at the neck, inflection point, and at the maximum diameter. In initial studies, the influence of pressurization and the mechanical properties of AAA wall stress were evaluated. In subsequent studies, the latex AAAs were excluded with a tube graft and retested in the PFM. After creation of either a type I or II endoleak of known size and pressure, the systemic/intrasac pressure and the AAA wall stress were measured. Results: Each model had a complex wall-stress pattern comprising radial, longitudinal, and shear components. The peak wall stress at any point, in the presence of systemic pressurization or endoleak pressure, only reached 1% of the failure strength. In an AAA with a reinforced wall, the peak stress was significantly greater. Statistical analysis showed that wall strength contributed more significantly to wall stress than increasing pressurization within the AAA sac. Conclusions: AAA wall mechanics contribute more significantly to peak wall stress than pressure variations within the system. In particular, increased stiffness (analogous to collagen deposition) significantly increased peak wall stress, which was located at the inflection point rather than at the maximum diameter. Techniques to measure the AAA wall mechanics and the rate of deterioration may predict AAA rupture in the untreated state or in the presence of an endoleak following endovascular repair.

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Kunchariyakun, Kittipong, Suwimol Asawapisit, and Kwannate Sombatsompop. "The Effect of Rice Husk Ash on Properties of Aerated Concrete." Advanced Materials Research 747 (August 2013): 420–23. http://dx.doi.org/10.4028/www.scientific.net/amr.747.420.

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In this study, rice husk ash (RHA) was used as an aggregate with different replacement levels (0%, 25%, 50%. 75% and 100%) to produce aerated concrete under normal and high-pressure steam curing at 180°C for 8 h. The physical and mechanical properties and microstructure analysis were examined. Results showed that the unit weight and compressive strength reduced when RHA was introduced. Both curing conditions have no significant effect on the unit weight, but high-pressure steam curing resulting in higher compressive strength of aerated concrete. Scanning electron microscopy (SEM) analysis reveals that crystalline tobermorite was detected in aerated concrete with high-pressure stream curing, whereas fibrous-CSH was found in aerated concrete with normal curing. Moreover, aerated concrete under high-pressure steam curing with 75% and 100% RHA dosages meet the requirement of ASTM C1368 for AAC-6 and AAC-4, respectively.

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Shen, Qingkai, Xiangdong Kong, and Xizhang Chen. "Fabrication of bulk Al-Co-Cr-Fe-Ni high-entropy alloy using combined cable wire arc additive manufacturing (CCW-AAM): Microstructure and mechanical properties." Journal of Materials Science & Technology 74 (May 2021): 136–42. http://dx.doi.org/10.1016/j.jmst.2020.10.037.

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Algaifi, Hassan Amer, Abdeliazim Mustafa Mohamed, Eyad Alsuhaibani, Shahiron Shahidan, Fahed Alrshoudi, Ghasan Fahim Huseien, and Suhaimi Abu Bakar. "Optimisation of GBFS, Fly Ash, and Nano-Silica Contents in Alkali-Activated Mortars." Polymers 13, no. 16 (August 16, 2021): 2750. http://dx.doi.org/10.3390/polym13162750.

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Although free-cement-based alkali-activated paste, mortar, and concrete have been recognised as sustainable and environmental-friendly materials, a considerable amount of effort is still being channeled to ascertain the best binary or ternary binders that would satisfy the requirements of strength and durability as well as environmental aspects. In this study, the mechanical properties of alkali-activated mortar (AAM) made with binary binders, involving fly ash (FA) and granulated blast-furnace slag (GBFS) as well as bottle glass waste nano-silica powder (BGWNP), were opti-mised using both experimentally and optimisation modelling through three scenarios. In the first scenario, the addition of BGWNP varied from 5% to 20%, while FA and GBFS were kept constant (30:70). In the second and third scenarios, BGWNP (5–20%) was added as the partial replacement of FA and GBFS, separately. The results show that the combination of binary binders (FA and GBFS) and BGWNP increased AAM’s strength compared to that of the control mixture for all scenarios. In addition, the findings also demonstrated that the replacement of FA by BGWNP was the most significant, while the effect of GBFS replacement by BGWNP was less significant. In particular, the highest improvement in compressive strength was recorded when FA, GBFS, and BGWNP were 61.6%, 30%, and 8.4%, respectively. Furthermore, the results of ANOVA (p values < 0.0001 and high F-values) as well as several statistical validation methods (R > 0.9, RAE < 0.1, RSE < 0.013, and RRSE < 0.116) confirmed that all the models were robust, reliable, and significant. Similarly, the data variation was found to be less than 5%, and the difference between the predicted R2 and adj. R2 was very small (<0.2), thus confirming that the proposed non-linear quadratic equations had the capability to predict for further observation. In conclusion, the use of BGWNP in AAM could act as a beneficial and sustainable strategy, not only to address environmental issues (e.g., landfill) but to also enhance strength properties.

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Arunbabu, Dhamodaran, Hamed Shahsavan, Wei Zhang, and Boxin Zhao. "Poly(AAc-co-MBA) Hydrogel Films: Adhesive and Mechanical Properties in Aqueous Medium." Journal of Physical Chemistry B 117, no. 1 (December 21, 2012): 441–49. http://dx.doi.org/10.1021/jp3101688.

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Adediran, Yliniemi, and Illikainen. "Fayalite Slag as Binder and Aggregate in Alkali-Activated Materials—Interfacial Transition Zone Study." Proceedings 34, no. 1 (November 18, 2019): 1. http://dx.doi.org/10.3390/proceedings2019034001.

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Alkali-activated materials (AAMs) are an environmentally friendly option for Portland cement mortars and concretes. Many industrial residues such as blast furnace slag and coal fly ash have been extensively studied and applied as AAM precursors but much less focus has been on the use of fayalite slags. Water-cooled fayalite slag comes in granular form, which is then milled into fine powder (d50 ~10 microns) prior to its alkali activation. In addition, the un-milled granular fayalite slag can be used as an aggregate to replace sand in mortar. The alkaline solution utilized for the study was a mix of 10 M sodium hydroxide solution and commercial potassium silicate solution. A liquid to solid ratio of 0.15 was held constant for all the mixes. The particle size distributions of the binder and the aggregates were optimized, and the microstructure and chemical composition of the interfacial transition zone (ITZ) was studied using scanning electron microscope coupled with energy dispersive X-ray spectroscopy. ITZ is a region that exists between the aggregate and the binder and this can influence the mechanical and transport properties of the construction materials. The results showed that the mechanical properties of mortar having fayalite slag as aggregate and binder was significantly higher than one with standard sand as aggregate. No distinct ITZ was found in the samples with fayalite slag as aggregate. The outer rim of the fayalite slag aggregate participated in the hardening reaction and this significantly contributed to the bonding and microstructural properties of the mortar samples. In contrast, an ITZ was observed in mortar samples with standard sand aggregates, which contributed to its lower strength.

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BERNIK, Rajko, and Filip VUČAJNK. "Vpliv globine obdelave tal z vrtavkasto brano na porabo energije in pripravo setvenega sloja pred setvijo koruze." Acta agriculturae Slovenica 111, no. 3 (December 12, 2018): 671. http://dx.doi.org/10.14720/aas.2018.111.3.15.

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In 2012 on the Laboratory Field of Biotechnical Faculty the field trial was carried out, trying to establish the influence of the soil cultivation on the fuel consumption, on the physical-mechanical soil properties of the seed bed and at the end on the field emergence of maize. A rotary harrow was used for soil preparation just before maize planting and it was adjusted to the soil cultivation depths of 5 cm, 10 cm and 15 cm. The trial was designed as random blocks. A tractor with stepless transmission and nominal power of 73 kW and a rotary harrow with working width of 2.5 m were used. The speed of soil cultivation was 5.0 km h<sup>-1</sup> on the tractometer and the engine rotational frequency was 1900 rpm. The fuel consumption per hour, the fuel consumption per hectare and the energy consumption per hectare increased by increasing the adjusted soil depth cultivation from 5 cm to 15 cm using the rotary harrow. At the adjusted soil cultivation depth of 10 and 15 cm cm, the vertical soil resistance at depths between 8 and 13 cm was lower than at the adjusted soil depths of 5 cm. No significant differences were found regarding the soil physical properties in the seed bed and the field emergence of maize among three adjusted soil cultivation depths. The soil cultivation depth of 10 cm proved to be the most appropriate in view of the fuel consumption, energy consumption as well as the physical-mechanical soil properties of the seed bed and plant emergence.

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Mingliang, Qu, Tian Shuaiqi, Fan Liwu, Yu Zitao, and Ge Jian. "Thermal Conductivity of Silica-aerogel (SA) and Autoclave Aerated Concrete (AAC) Composites." E3S Web of Conferences 172 (2020): 21007. http://dx.doi.org/10.1051/e3sconf/202017221007.

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Improving the thermal insulating performance of porous building materials is of great practical significance for building energy conservation. In this work, silica aerogels (SA) with ultralow thermal conductivity were proposed as an appropriate candidate to be integrated with autoclaved aerated concrete (AAC) to produce novel SA-AAC composites with higher thermal insulating performance by physical solution impregnation method. The pore-structures, mechanical and thermal properties of the SA-AAC composites were probed by various experimental tests. According to the microscopy and porosimetry results, SA were observed to adhere to the surface walls of the AAC holes, thus reducing the amount of macro-sized pores. In addition, the improved thermal insulating performance of AAC was successfully achieved with the relative improvement depending on the porosity of the pristine AAC. At the mass fraction of SA of ~7%, the highest relative improvement was found to be ~30% The results of this work exhibited a great potential of this novel SA-AAC composite in engineering applications.

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Kawa, Ernawati, Minsyahril Bukit, and Albert Zicko Johannes. "PENENTUAN SIFAT MEKANIS DAN FISIS BATU BATA DENGAN PENAMBAHAN ARANG TEMPURUNG KELAPA ASAL ALOR." Jurnal Fisika : Fisika Sains dan Aplikasinya 3, no. 1 (December 17, 2018): 80–85. http://dx.doi.org/10.35508/fisa.v3i3.605.

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Abstrak Telah dilakukan penelitian tentang penentuan sifat mekanis dan fisis batu bata dengan penambahan tempurung kelapa asal alor. Penenlitian ini bertujuan mengetahui kualitas batu bata yang memenuhi standar kelayakan sebagai bahan konstruksi dengan penambahan arang tempurung kelapa aal alor dengan presentasi 0%, 5%, 10%, 15% terhadap tanah liat (lempung). Batu bata dicetak dengan prosedur pemadatan, pengringn dan pembakaran. Setelah prosedur pencetakkan selesai kemudian di lanjutkan dengan pengujian sefat mekanis dan sifat fisis, yaitu uji kuat tekan (compression strength), densitas (density), porositas (porosity) hasil kuat tekan batu bata didapatkan berdasarkan pengujian: a) uji kuat tekan, batu bata tanpa penambahan (0%) : 4,94 meemenuhi standar kuat tekan kelas 50 (SNI 15-2094-2000), b) uji porositas, batu bata 0% dan 5% : 3,82% dan 17,93% memenuhi standar porositas dengan batas maksimum 20% (SNI 15-2094-2000) dan uji densitas, batu bata tidak ada yang memenuhi standar (SII 0021-1978) Kata kunci: sifat mekanis, sifat fisis, tempurung kelapa, densitas, porositas, kuat tekan Abstract A research had been conducted to determine physical and mechanical properties of the bricks with the addition coconut shell charcoal from alor. This research aims at the quality of the bricks to meet the standars of eligibility as a contruction material. The addition of coconut shell charcoal is variate with the presentage 0%, 5%, 10%, 15% to the clay mass. The brick being printed with procedure compaction, drying, and baking. After the printing procedure is done then next is testing the mechanical and physical properties, that is compression strength test, density test, and porosity test. The brick quality result is obtained based on the test: a) compression strength test, the brick without addition (0%) : 4,94 (SNI 15-2094-2000) is comply with the standard compression strength the class 50 , b) porosity test, the brick 0% and 5% (3,82% and 17,93%) meet the standard with the maximum limit 20% ( SNI 15-2094-2000) , and c) density test, every bricks does not meet the standard (SII 0021- 1978). Keywords: mechanical properties, physical properties, coconut shell, density, porosity, compression strength

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48

Milovanovic, Marko, Lydia Mihailowitsch, Mathusiha Santhirasegaran, Volker Brandt, and Joerg C. Tiller. "Enzyme-induced mineralization of hydrogels with amorphous calcium carbonate for fast synthesis of ultrastiff, strong and tough organic–inorganic double networks." Journal of Materials Science 56, no. 27 (June 23, 2021): 15299–312. http://dx.doi.org/10.1007/s10853-021-06204-6.

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Abstract Hydrogels with good mechanical properties have great importance in biological and medical applications. Double-network (DN) hydrogels were found to be very tough materials. If one of the two network phases is an inorganic material, the DN hydrogels also become very stiff without losing their toughness. So far, the only example of such an organic–inorganic DN hydrogel is based on calcium phosphate, which takes about a week to be formed as an amorphous inorganic phase by enzyme-induced mineralization. An alternative organic–inorganic DN hydrogel, based on amorphous CaCO3, which can be formed as inorganic phase within hours, was designed in this study. The precipitation of CaCO3 within a hydrogel was induced by urease and a urea/CaCl2 calcification medium. The amorphous character of the CaCO3 was retained by using the previously reported crystallization inhibiting effects of N-(phosphonomethyl)glycine (PMGly). The connection between organic and inorganic phases via reversible bonds was realized by the introduction of ionic groups. The best results were obtained by copolymerization of acrylamide (AAm) and sodium acrylate (SA), which led to water-swollen organic–inorganic DN hydrogels with a high Young’s modulus (455 ± 80 MPa), remarkable tensile strength (3.4 ± 0.7 MPa) and fracture toughness (1.1 ± 0.2 kJ m−2). Graphical Abstract The present manuscript describes the method of enzymatic mineralization of hydrogels for the production of ultrastiff and strong composite hydrogels. By forming a double-network structure based on an organic and an inorganic phase, it is possible to improve the mechanical properties of a hydrogel, such as stiffness and strength, by several orders of magnitude. The key to this is the formation of a percolating, amorphous inorganic phase, which is achieved by inhibiting crystallization of precipitated amorphous CaCO3 with N-(phosphonomethyl)glycine and controlling the nanostructure with co polymerized sodium acrylate. This creates ultrastiff, strong and tough organic–inorganic double-network hydrogels.

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49

Iucolano, Fabio, Assunta Campanile, Domenico Caputo, and Barbara Liguori. "Sustainable Management of Autoclaved Aerated Concrete Wastes in Gypsum Composites." Sustainability 13, no. 7 (April 2, 2021): 3961. http://dx.doi.org/10.3390/su13073961.

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Promoting the use of gypsum and gypsum-based materials in construction is a successful strategy from an environmental point of view; it allows a lower energy demand with a sensible reduction in carbon dioxide emissions. At the same time, the manufacturing of gypsum products can represent an interesting sector to redirect and manage the large amount of autoclaved aerated concrete (AAC) waste. In this paper a sustainable application of AAC granulate waste in gypsum-based building materials was proposed. The intrinsic compatibility derived their chemical composition and allowed it to partially substitute raw gypsum with the waste up to 30% without affecting the functional and structural properties of the final product. Physical characterization and sound absorption data confirmed that the addition of AAC waste does not significantly alter the typical porosity of the gypsum composite. Finally, all of the composites reached mechanical performances suitable for different building application as gypsum plaster.

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50

Wu, Te Hsing, Hong Ru Lin, and Lie Han Shen. "Preparation and Properties of Nanocomposites Containing FGF-2, other Related Dressings and the Primary Animal Tests." Advanced Materials Research 535-537 (June 2012): 406–10. http://dx.doi.org/10.4028/www.scientific.net/amr.535-537.406.

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PU/ hydrogel composites or it containing fibroblast growth factor-2 (FGF-2) composites had been prepared by γ-ray radiation or room temperature(T) method in this paper. We utilized nanosized clay solution, thermosensitive N-isopropyl acrylamide (NIPAAm), Polyurethane (PU), and acrylic acid (AAc) as the starting materials to synthesize PU/hydrogel nanocomposite products. The dipping and weighing tests, Material Testing Machine (LLOYD) were employed to analyze the physical and mechanical properties differentially. In addition, the drug release and the wound closure in animal experiments were also finished by Enzyme-link immunosorbent assay( ELISA) reader and magnifier for five groups of treatment dressings. From the experimental results, we distinctly obtained that animal tests of the PU/hydrogel composite incorporating FGF-2 as a wound dressing was able to effectively interact with the wound in a suitable moist healing environment. From the results, we also gained that these composites make themselves more compatible with skin.

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Journal articles on the topic 'Physical-mechanical properties of AAM'

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