Dissertations / Theses on the topic 'High strength concrete Effect of temperature on'
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Acquaye, Lucy. "Effect of high curing temperatures on the strength, durability and potential of delayed ettringite formation in mass concrete structures." [Gainesville, Fla.] : University of Florida, 2006. http://purl.fcla.edu/fcla/etd/UFE0013837.
Full textTSIMBROVSKA, MARIANA. "Dégradation des bétons à hautes performances soumis à des températures élevées : évolution de la perméabilité en liaison avec la microstructure." Université Joseph Fourier (Grenoble), 1998. http://www.theses.fr/1998GRE10030.
Full textMarquis, Glenn M. "Effect of high-strength concrete on the seismic response of concrete frames." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ37270.pdf.
Full textSheikh, Vassiem. "Fresh properties, temperature rise and strength development of high strength concrete with binary and tertiary blended cements." Thesis, University College London (University of London), 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.395651.
Full textGhannoum, Carla M. "Effect of high-strength concrete on the performance of slab-column specimens." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0027/MQ50609.pdf.
Full textGhannoum, Carla M. "Effect of high-strength concrete on the performance of slab-column specimens." Thesis, McGill University, 1998. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=21294.
Full textThe second part of this thesis is a comparison of the test results obtained from this experimental program with the punching shear predictions of the Canadian CSA A23 3-94 Standard and the American ACI 318-95 Code. Some comparisons of the punching shear strength provisions of the British BS 8110-85 Standard and the European CEB-FIP 1990 Model Code are also carried out. Furthermore, the CSA Standard and the ACI Code predictions are compared to the experimental results obtained from some slab-column connections tested in this experimental program and tested by various investigators.
The beneficial effects of the use of high-strength concrete and of the concentration of flexural reinforcement in the immediate column vicinity are demonstrated. It is also concluded that the punching shear strength of slab-column connections is a function of the flexural reinforcement ratio and that the shear design of slabs according to the current Canadian and American codes can be unconservative under certain conditions. It is recommended that the punching shear expressions of the CSA Standard and the ACI Code be modified to include the effect that the flexural reinforcement ratio has on the shear capacity of slab structures.
Trende, Uwe. "Interface fracture mechanics of high strength concrete : size effect and aggregate roughness." Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/11812.
Full textGriškevičius, Mečislavas. "High Temperature Effect On Resistance Of Timber Structures." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2010. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2010~D_20101119_134602-29128.
Full textDisertacijoje nagrinėjami pušinės ir ąžuolinės medienos stipruminių savybių pokyčių temperatūriniai sąryšiai bei medinių centriškai gniuždomų liaunų elementų elgsena veikiant aukštesnėms temperatūroms. Pagrindiniai tyrimo objektai yra Lietuvos spygliuočių ir lapuočių medienos savybių pokyčiai didėjant temperatūrai ir centriškai gniuždomų liaunų medinių elementų elgsenos veikiant kaitrai eksperimentiniai tyrimai bei rezultatų lyginamoji analizė. Darbe spręsti tokie pagrindiniai uždaviniai: gauti eksperimentinius duomenis apie aukštos temperatūros poveikį skirtingos natūralios – pušinės ir ąžuolinės – medienos savybėms, atlikti centriškai gniuždomų liaunų medinių elementų elgsenos ugnyje tyrimus. Atsižvelgiant į tyrinėtą tikrovišką gaisro poveikį patikslinti esamą EN 1995-1-2 medinių liaunų gniuždomų elementų atsparumo ugniai skaičiavimo metodiką. Disertaciją sudaro įvadas, penki skyriai, bendrosios išvados, naudotos literatūros ir autoriaus publikacijų disertacijos tema sąrašai ir du priedai. Pirmasis skyrius skirtas literatūros apžvalgai. Jame pateikta darbų, kuriuose nagrinėjamas aukštesnės temperatūros veikiamos medienos, stipruminių savybių mažėjimas ir kuriuose pateikiami gaisro sąlygomis gniuždomų medinių elementų laikomosios galios tyrimų rezultatai. Pabaigoje formuluotos išvados ir disertacijos tikslai ir uždaviniai. Antrajame skyriuje pateikta medienos stipruminių savybių aukštesnėse temperatūrose tyrimo metodika ir sukurtų nestandartinių bandymo įrenginių schemos... [toliau žr. visą tekstą]
De, Carufel Sarah. "Effect of High-Performance Steel Materials on the Blast Behaviour of Ultra-High Performance Concrete Columns." Thesis, Université d'Ottawa / University of Ottawa, 2016. http://hdl.handle.net/10393/35380.
Full textKim, Byoungil. "Effect of fiber types on the mechanical properties and permeability of high strength concrete." [Gainesville, Fla.] : University of Florida, 2006. http://purl.fcla.edu/fcla/etd/UFE0015827.
Full textMelançon, Christian. "Effect of High-Performance Concrete and Steel Materials on the Blast Performance of Reinforced Concrete One-Way Slabs." Thesis, Université d'Ottawa / University of Ottawa, 2016. http://hdl.handle.net/10393/34102.
Full textAzizipesteh, Baglo Hamid Reza. "Effect of various mix parameters on the true tensile strength of concrete." Thesis, Loughborough University, 2013. https://dspace.lboro.ac.uk/2134/12560.
Full textMansour, Marwan. "Experimental tests on the effect of temperature on the short term behavior of FRC beams." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021.
Find full textRanjbar, Sahar. "Effect of pre-wetted perlite and fibers on autogenous and plastic shrinkage of high strength concrete." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/44023.
Full textEvans, Christopher Michael. "The influence of fly ash and early-age curing temperature on the durability and strength of high-performance concrete." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ28830.pdf.
Full textMahmoud, Karam Abdou Awad. "Shear behaviour of continuous concrete beams reinforced with GFRP bars." ASCE, 2015. http://hdl.handle.net/1993/30951.
Full textFebruary 2016
Li, Jieren. "The combined effect of silica fume and fly ash on microstructure and properties of high-strength concrete." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0035/NQ38485.pdf.
Full textYahya, Mohmed Alkilani. "The effect of polymer materials on the fracture characteristics of high performance concrete (HPC)." Thesis, Edinburgh Napier University, 2015. http://researchrepository.napier.ac.uk/Output/464157.
Full textKhokhar, Muhammad Irfan. "Optimisation of concrete mix design with high content of mineral additions: effect on microstructure, hydration and shrinkage." Doctoral thesis, Universite Libre de Bruxelles, 2010. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209985.
Full textlinked to the decarbonation of limestone conducted at high temperature and results in a
significant release of CO2. This thesis is part of the project EcoBéton (Green concrete) funded
by the French National Research Agency (ANR), with a purpose to show the feasibility of
high substitution of cement by mineral additions such as blast furnaces slag, fly ash and
limestone fillers. Generally for high percentages of replacements, the early age strength is
lower than Portland cement concrete. To cope with this problem, an optimisation method for
mix design of concrete using Bolomey’s law has been proposed. Following the encouraging
results obtained from mortar, a series of tests on concretes with different substitution
percentages were carried out to validate the optimisation method. To meet the requirements of
the construction industry related to performance of concrete at early age, which determine
their durability, a complete experimental study was carried out. Standard tests for the
characterization of the mechanical properties (compressive strength, tensile strength, and
setting) allowed to validate the choice of mix design on the basis of equivalent performance.
We focused on the hydration process to understand the evolution of the mechanical
properties. Setting time measurement by ultrasound device at different temperatures (10°C,
20°C and 30°C) showed that ground granulated blast furnace slag (GGBFS) and fly ash
delayed the setting process, while use of limestone filler may accelerate this process.
Calorimetric studies over mortars and concretes made possible to calculate the activation
energy of the different mixtures and a decrease in heat of hydration of concretes with mineral
additions was observed which is beneficial for use in mega projects of concrete. Scanning
Electron Microscopy observations and thermal analysis have given enough information about
the hydration process. It was observed that the hydration products are similar for different
concrete mixtures, but the time of their appearance and quantity in the cement matrix varies
for each concrete mix.
Last part of the thesis was dedicated to the study of main types of shrinkage. First of all,
deformations measured were correlated to hydration, capillary depression and porosity
evolution. Results allowed concluding that the use of mineral additions has an actual effect on
the plastic shrinkage behaviour, but its impact is not proportional to the percentage of
additions. Substitution of cement by the additions seems to have a marked influence on the
kinetics of the shrinkage without any effect on its long term amplitude. The study of
restrained shrinkage under drying conditions by means of ring tests showed that concretes
with high percentage of slag addition seem more prone to cracking than the Portland cement
concretes.
Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished
Nince, Andréia Azeredo. "Lascamento do concreto exposto a altas temperaturas." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/3/3146/tde-27072007-143816/.
Full textThe present research was motivated by the going controversy in the literature about concrete exposed to high temperatures, the yet unanswered doubts existent on this subject and in the absence of regulation on the matter in Brazil. The theme gained significance after the occurrence of several accidents in tunnels all over the world in the last ten years, in which were observed a very intense form of explosive spalling that affected structural stability of the sites. The main purpose of this work is set up a correlation between technological parameters of dosage in concrete (water cement rate -w/c, mortar content - a, and total water consumption - H) and risk conditions of spalling, which are related to environment humidity that indirectly effects concrete saturation level. The second goal is to optimize the use of polypropylene fiber in order to minimize spalling. The standard H curve was applied during 55 minutes in cubic samples with only a single surface exposed to heat and with restrained lateral thermo dilatation. The response variable was the observed volume of spalling (with multiplied by area of spalling in the sample). The results showed the rate water/cement as the most relevant technology parameter related to spalling risk conditions. Whereas the use of fiber is concerned, efficiency required different fiber content and characteristic for each water/cement rate combined with higher environment humidity provides proper conditions for the occurrence of spalling were 600g/m³ and 1750g/m³ for water/cement ratios of 0,5 and 0,25 respectively. It was also found that the fiber with L=12mm, F=36µm PF=140°C was the most effective in reducing spalling for a water/cement ratio of 0,50 whilst for a effective in reducing spalling for a water/cement ratio of 0,50 whilst for a water/cement ratio of 0,50 whilst for a water/cement ratio 0,25 only the length (L=6 mm) appeared as a significant factor.
Nilforoush, Rasoul. "Anchorage in Concrete Structures : Numerical and Experimental Evaluations of Load-Carrying Capacity of Cast-in-Place Headed Anchors and Post-Installed Adhesive Anchors." Doctoral thesis, Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-66333.
Full textEppers, Sören. "Assessing the autogenous shrinkage cracking propensity of concrete by means of the restrained ring test." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2011. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-65454.
Full textDas durch Selbstaustrocknung verursachte autogene Schwinden von besonders leistungsfähigen Betonen mit sehr niedrigem Wasserzementwert führt bei Dehnungsbehinderung bereits in sehr frühem Alter zu erheblichen Zwangsspannungen. Die Gefahr der Rissbildung, die sich daraus ergibt, lässt sich bislang nur unzureichend untersuchen. Experimentell besonders schwer zu erfassende Faktoren sind die Betontemperatur und die Viskoelastizität. Das vorrangige Ziel der Arbeit war die möglichst genaue Ermittlung der autogenen Schwindrissneigung repräsentativer Betone bei starker Dehnungsbehinderung und konstanter Raumtemperatur. Dabei waren die Prüfverfahren möglichst so zu wählen und weiterzuentwickeln, dass sich zukünftig alle relevanten Faktoren effizient und genau untersuchen lassen. Im Idealfall sollte eine Methode entstehen, die eine vollständige empirische Modellierung erlaubt. Zunächst wurden die methodischen Anforderungen und die Vor- und Nachteile existierender Prüfverfahren diskutiert. Darauf aufbauend wurden optimierte Verfahren vorgeschlagen. Ihre Eignung wurde an ultrahochfestem Beton überprüft. Bei der Auswahl der Betone wurden die wesentlichen Maßnahmen zur Schwindreduzierung berücksichtigt (innere Nachbehandlung, schwindreduzierende Zusatzmittel, Verringerung des Portlandzementanteils am Bindemittel). Das autogene Schwinden wurde mit dem Schwindkegelverfahren gemessen. Das neue Verfahren wurde durch Untersuchungen zur Wiederhol- und Vergleichsgenauigkeit validiert und erwies sich als effizient und genau. Es ermöglicht Messungen unter nicht-isothermen Bedingungen; hierfür existiert bisher kein etabliertes Verfahren. Das autogene Schwinden der untersuchten ultrahochfesten Betone unter quasi-isothermen Bedingungen (20 °C) betrug im Alter von 24 h zwischen 0,25 mm/m und 0,70 mm/m. Besonders gering war es bei Zugabe eines schwindreduzierenden Zusatzmittels bzw. Verwendung superabsorbierender Polymere. Mit dem Ring-Test wurden die bei Dehnungsbehinderung entstehenden Spannungen ermittelt. Ein großer Teil der gemäß Hooke’schem Gesetz zu erwartenden Spannungen wurde durch Kriechen und Relaxation abgebaut. Die im sehr frühen Alter stark ausgeprägte Relaxationsfähigkeit war der wesentliche Grund dafür, dass es selbst bei Betonen mit hohem autogenen Schwinden zu keiner erkennbaren Rissbildung kam. Die Entwicklung der autogenen Schwindrissneigung wurde als Verhältnis von Zwangsspannung und Spaltzugfestigkeit beschrieben. Durch modifizierte Ring-Tests, mit deren Hilfe die maximale Zugspannung ermittelt wurde, konnte gezeigt werden, dass das Verhältnis von Spannung und Festigkeit als Versagenskriterium geeignet ist. Die Rissneigung lässt sich aber nur dann korrekt berechnen, wenn das stark altersabhängige Verhältnis von einaxialer Zugfestigkeit und Spaltzugfestigkeit berücksichtigt wird. Außerdem ist zu beachten, dass es im sehr frühen Alter zu einer plastischen Spannungsumlagerung in Ring-Tests kommen kann. Der Referenzbeton wies eine hohe Rissneigung von bis zu 0,68 auf. Dass die schwindreduzierenden Maßnahmen zu deutlich geringeren Werten führten, zeigt deren Bedeutung für den sicheren Einsatz von ultrahochfestem Beton. Die hier bei 20 °C durchgeführten Untersuchungen erlauben allerdings keine abschließende Bewertung der Rissneigung unter baustellentypischen Bedingungen. Um die autogene Schwindrissneigung zukünftig als Funktion der Temperatur und des Lastniveaus empirisch modellieren zu können, wurden eine analytische Spannungslösung für nicht-isotherme Ring-Tests und ein neuer Ansatz zur Untersuchung der Resttrag- und Relaxationsfähigkeit mit Hilfe nicht-passiver Ring-Tests vorgeschlagen
Miah, Md Jihad. "The effect of compressive loading and cement type on the fire spalling behaviour of concrete." Thesis, Pau, 2017. http://www.theses.fr/2017PAUU3015/document.
Full textThe research presented in this thesis seeks to examine and understand the mechanism of fire spalling role played by the external compressive loading during heating. Concrete cube (200 x 200 x 200 mm3) and slab (800 x 800 x 100 mm3) specimens made with CEM II and CEM III cements (B40-II and B40-III: fc28days ≈ 40 MPa) were exposed to ISO 834-1 fire curve under different levels of external uniaxial (for cube) and biaxial (for slab) compressive stress. Additionally, the effect of external compressive loading (confining pressure and uniaxial load) on the residual gas permeability of concretes have been investigated. In order to better analyse the experimental results and to provide more insight into the mechanism behind the fire spalling behaviour of concrete, numerical computations were carried out by using the existing thermo-mechanical model implemented in a finite element code CAST3M. The experimental results have clearly shown that the loaded specimens (uniaxial and biaxial) are more prone to spalling than unloaded specimens, with increasing amounts of spalling for higher values of applied compressive stress. Part of the tests, but not all have shown that B40-II (3% of slag) exhibited higher spalling than the B40-III (43% of slag).From this study on two ordinary concretes, it highlights that a certain level of external compressive stress (uniaxial or biaxial) was necessary to induce spalling. A possibility is that the applied compressive stress prevents the creation of cracks naturally due to thermal mismatch between cement paste and aggregates and thermal gradients. For unloaded specimen, the creation of cracks increases the permeability and naturally prevents the pore pressure to exceed a value that favours spalling.During a real fire, concrete structural members are always loaded or restrained. The presence of compressive loading during heating significantly increases the compressive stress (decreases the tensile stress) and the magnitude of pore pressure, which increase the risk of fire spalling. Then, the applied compressive stress is a very important key factor that the fire resistance design of concrete structures should take into account when considering spalling. Hence, it is recommended that the fire spalling test should not be carried out only on unloaded specimens, especially for the ordinary concrete
Pereira, Tobias Azevedo da Costa. "Concreto auto-adensável, de alta resistência, com baixo consumo de cimento Portland e com adições de fibras de lã de rocha ou poliamida." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/18/18134/tde-14012011-104648/.
Full textThe aim of this work is to show a methodology that allows to realize a set of high strength self-consolidating concrete, economic and with lower environmental impact when compared with current concretes. To get these results, criteria for production and mix design had been established aiming at to synergy between constituent materials of the concrete. Methods of particles packing (aggregates and mineral additions), the interaction between the superplasticizer and cementitious materials and the fiber incorporation were researched. The concretes with dense matrix under effect of high temperatures are susceptible to explosive spalling. In this situation, concretes were evaluated by testing cylindrical specimens and results evidenced the importance of the polyamide fiber when the concrete supported 400ºC. Tests of abrasion resistance indicated a good application for the wool-of-rock fiber, but this material not avoids explosive spalling. The mechanical properties of the concretes were determined and show that is possible to product a self consolidate concrete with low cement content (325 kg/\'M POT.3\'), fc7 = 53 MPa, fc28 = 71 MPa and Ec28 = 43 GPa. Due to action of the mineral additions, these concretes had a great reserve of compressive strength after the age of reference of 28 days and achieved 89 MPa at 131 days of age. The high density cement paste, the improvement of the matrix-aggregate interfacial zone and the reduced cracking due to the low cement content and the fibre addition indicate that these materials has superior performance to those prescribed for the NBR 6118 for diverse strength classes and aggressive environmental exposure.
OBADIA, BAROGHEL SYLVIA. "Frittage de melanges al::(2)o::(3) + sio::(2) gel pour moules de fonderie : developpement des microstructures et deformation a chaud." Paris, ENMP, 1987. http://www.theses.fr/1987ENMP0079.
Full textCastillo, Carlos. "Effect of transient high temperature on high-strength concrete." Thesis, 1987. http://hdl.handle.net/1911/13275.
Full textChang, Yen-Shiang, and 張晏祥. "EFFECT OF HIGH TEMPERATURE ON THE MACRO- AND MICRO-PROPERTIES OF HIGH STRENGTH CONCRETE." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/68233472311136753617.
Full textYeh, Ming-Jia, and 葉明家. "The Effects of Fire-Retardant Coating on Strength of Concrete under High Temperature." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/56898374716502358124.
Full text國立屏東科技大學
土木工程系所
98
Student ID: N9633018 Title: The Effects of Fire-Retardant Coating on Strength of Concrete under High Temperature Pages: 49 Name of Institute: National Pingtung University of Science and Technology Name of Department: Department of Civil Engineering Date of Graduation: January 2010 Degree Conferred: Master Name of student: Ming-Jia Yeh Adviser: Dr. Jun-Kai Lu Abstract content: Fire-Retardant Coatings are used wildly in wooden building, steel structures and interior partitions. It is hardly used in concrete structure. The concrete are very popular material for structure in Taiwan. The mechanical behaviors of concrete are changing with respected to the changing of temperature. Present paper investigates the effects of the Fire-Retardant Coating on strength of concrete under high temperature. Three different Fire-Retardant Coatings are investigated. Five different temperatures are discussed in present paper. There are room temperature, 400℃,500℃,600℃,700℃. It is shown that the strength of concrete specimen with Fire-Retardant Coating are high than the strength of concrete specimen without fire-retardant coating. Also, the strength of concrete specimen with different fire-retardant coating is different from each other.
EN, LEE CHEN, and 李承恩. "The Effects of Fire Resistance Materials on Strength of Concrete and Bonding Strength of Rebar under High Temperature." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/69vhk8.
Full text逢甲大學
土木工程學系
107
This study is to investigate the difference in compressive strength and the bonding strength between concrete specimens and specimens coated with fire resistance material under various fire temperatures. There are a total of 84 concrete cylindrical specimens with dimensions of ∅12cm×24cm, in which 21 specimens are embedded with 22 cm length of #4 rebar and 24 specimens with different embedment length of #3 rebar, all with design strength of 245 kgf/〖"cm" 〗^"2" . The experimental parameters include the thickness of fire resistance material coating, fire temperature, and fire exposure duration. The concrete compression test and pullout test of concrete specimens and reinforced concrete specimens are made after the specimens are exposed to fire. From the test results, the compressive strength of concrete cylindrical specimen decreases less as the thickness of fire resistance material increases, with a better fire protection effect. The pullout strength of reinforced concrete specimen drops less as the thickness of fire resistance material increases, with a better bonding strength protection effect. The results also show that the pullout strength of the specimen coated by the fire resistance material increases as the embedment length of rebar increases after being heated, with a better bonding force protection effect.
Hlabangana, Mthulisi. "Effect of high-volume fly ash, curing temperature and water to cement ratio on strength development and durability of concrete." Thesis, 2020. https://hdl.handle.net/10539/31341.
Full textHigh volume fly ash concrete presents a sustainable and environmentally friendly alternative to production of construction materials. However, it has not been fully embraced in high strength concrete applications due to the challenge of reduced early age compressive strength. This study investigated the influence of high volume fly ash replacement, curing temperature, water to cement ratio and Ca(OH)2 activation on compressive strength and durability of concrete. High strength concrete incorporating ordinary Portland cement and ultra-fine fly ash contents of 25%, 35% and 50% was used to prepare samples for compressive strength and durability testing. Ultra-fine fly ash was used in order to attain high strength concrete. A total of 16 concrete mixes were prepared. Eight concrete mixes had a w/c ratio of 0.45 and the other eight mixes had aw/c ratio of 0.35. Ca(OH)2 was added to eight concrete mixes in order to activate the fly ash and improve early age compressive strength and durability. Concrete cubes of 100mm dimensions were cast and cured in water at either 23⁰C or 40⁰C. The concrete properties measured included compressive strength, chloride conductivity, oxygen permeability and water absorption. Compressive strength tests were done at 1 day, 3 days, 7 days, 28 days, 90 days and 180 days. The results showed that some fly ash concrete mixes yielded higher compressive strength compared to the ordinary portland cement concrete mixes. Adding Ca(OH)2 and curing at 40⁰C significantly improved the rate of compressive strength development of fly ash concrete. Durability index tests were conducted at the age of 28 days in accordance with the South African durability index testing methods. Concrete with water to cement ratio of 0.35 yielded higher compressive strength and durability results compared to concrete with water to cement ratio of 0.45. Curing at 40⁰C reduced the late age strength of ordinary Portland cement concrete whereas curing at 40⁰C and adding Ca(OH)2 improved the strength of fly ash concrete. 50% fly ash concrete was the most responsive to Ca(OH)2 activation and high temperature curing. The chloride conductivity index for ordinary Portland cement concrete was significantly higher than that of fly ash concrete. Fly ash concrete cured at 40⁰C was more resistant to chloride penetration compared to fly ash concrete cured at 23⁰C. All the durability index test results signified concrete of high quality. An economic analysis for the binder material indicates that high volume fly ash replacement yielded significant economic benefits
CK2021
Wang, Tien-Chih, and 王天志. "Strength recovery of high performance concrete with polypropylene fiber after high temperature." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/00103855991742997785.
Full text國立交通大學
土木工程學系研究所
85
Abstract: The application of high performance concrete (HPC) has become in- creasingly popular. However, many researchers have concerned and question its propertiesafter high temperature. This study is aimed at the investigation of the residual compressive strength and the nondestructive testing behavior of H PC after high temperature. Although research studies showed that HPC will easily be explosive under high temperature, but Mobil Oil Company found that the addition of polypropylene fiber in HPC will reduce this problem. However, many researchers have still concerned about the recovery strength of high per- formance polypropylene fiber concrete (HPPC)after high temperature. This study is devoted to investigate the effects of high temperature ( Celsius degree:200 ,400,600,800 ) on the recovery strength of HPPC. The major experimental param- eters include cooling method (natural cooling,force cooling), re-curing method ( air curing,water curing ), and curing time ( 1,7,28,91 days). In addition, the impact-echo testing machine is used to study the nondestructive testing be havior of HPPC after high temperature. Furthermore, a correlation between the velocity of stress waveand compressive strength is estiblished.
Wang, Chun Wen, and 王俊文. "An Analyse on Concrete which Under High Temperature with Strength Change." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/10820847277773015638.
Full text國立雲林科技大學
營建工程研究所
88
An Analyse on Concrete which Under High Temperature with Strength Change Student:Wang, Chun Wen Advisors:Dr. Tsai, Cho Liang Institute of Construction Engineering National Yunlin University of Science & Technology ABSTRACT Under normal conditions of environment exposure, concrete is subjected to temperatures below about 50C. For many problems of concrete engineering, however, higher temperatures ranging from 50C to several hundred degrees Celsius can become of great importance. The first attempt at the study of concrete under high temperatures came from problems with the fire resistance of buildings. Concrete has excellent properties in this regard compared with most of traditional constructional materials and can be used effectively to shield other structural materials such as steel. The response of concrete to different temperature and exposure time needs to be studied if the fire resistant capability of the RC structure is to be estimated. The response of concrete to high temperature is complicated. Chemical and micromechanic behaviors of the concrete are not in the scope of this study. Experiments are conducted to characterize the macromechanic response. The residual strength of concrete after heat treatment is related to the temperature and exposure time mathematically from the analysis of the experimental data. The result can be used to predict the residual strength of concrete after any kind of heat treatment with variable temperature time history.
Lu, Chien-Chung, and 呂建忠. "Research on the Temperature Development of High-Strength Concrete at Early Age." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/50886806493483792880.
Full text國立中興大學
土木工程學系所
94
The High-Strength Concrete (HSC) generally containing high amount of cement and silica fume may generate large hydration heat at early age . The interior temperature of HSC will be increased dramatically and may result in a temperature crack. This research aims to investigate the interior temperature developments of HSC adding pozzolanic materials, such as silica fume and fly ash at early age. The research variables includes:three water-to-binder ratios (W/B) (0.25, 0.35, 0.40) , three silica fume contents (5%, 10%, 15%) , three fly ash contents (10%, 20%, 30%) and three sand contents (30%, 35%, 40%). Test results show that the initial and the maximum central temperature of the HSC decrease with the increase of W/B. However, W/B does not show a clear influence on the time to second hydration heat peak. Increasing the silica fume content level will enhance the initial temperature and shorten the time to reach the second hydration heat peak. In addition, by increasing the fly ash content level, it can have effects of delaying the time to the second hydration heat peak and also reducing the maximum temperature observed.
Xiao, Wan-Xuan, and 蕭宛瑄. "The Effect of Carbon Dioxide Curing on High Strength Pervious Concrete." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/6fa29n.
Full text國立中央大學
土木工程學系
106
In recent years, the global environmental protection has risen in the development of industry and changes of environment. Promoting the technology of carbon capture and storage in the world, and the way how to consume the carbon dioxide could become a part of the research. Using pervious concrete is one of the recommended methods to reduce the urban heat island effect. However, the pervious concrete is not so wide at all and the strength of pervious concrete is much lower than general concrete because of the permeability requirement. The research tried to produce a high strength pervious concrete and use carbon dioxide for curing to find out whether it could enhance the compressive strength. Two dimensions of cylinders are Φ10×20 cm and Φ15×30 cm samples for testing compressive strength, elastic modulus, abrasion resistance, X-ray diffraction (XRD) and Scanning Electron Microscope (SEM). The results show that the compressive strength of the control group increases rapidly and its 90-day compressive strength closed to 60 MPa. Although the porosity is less than 15%, the permeability coefficient complies with the regulations of ACI 522. The compressive strength has a major impact after 1 hour of CO2 curing and their strength decreased by about 0% to 23% as compared to the control group. This result is similar to the value of literature-based recommendation, 12000, and the aggregate with small particle size has a higher modulus of elasticity. The test results showed that abrasion resistance of high strength pervious concrete is about 0.06% weight loss less than the normal concrete and has excellent abrasion resistance properties. XRD analysis showed that the surface product of the test piece decreased with the increase of age, for example calcite, aragonite, vaterite, portlandite, quartz and ettringite, but the peak value has no obvious relationship with both the pressure and time of CO2 curing. SEM analysis revealed that the surface product of the test piece, such as ettringite, was increased after CO2 curing.
Tessema, Eden. "The effect of high strength concrete on the bondability of prestressing strands /." 2006. http://digital.library.okstate.edu/etd/umi-okstate-1858.pdf.
Full textTANG, ZHAO-WEI, and 湯兆緯. "Effect of confinement on the ductility of reinforced high-strength concrete beam." Thesis, 1988. http://ndltd.ncl.edu.tw/handle/88625296641524057927.
Full textJheng, Guan-wei, and 鄭冠威. "Effect of Fire on Compressive Strength of Early Cured High Performance Concrete." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/80688395868400507545.
Full text國立高雄第一科技大學
環境與安全衛生工程研究所
100
This study investigated the effect of high temperature on early cured concrete with and without fly ash (w/c=0.5). Parameters studied included the ratio of fine/coarse aggregates (1:1 and 1.5:1), curing duration (3, 7, 14, 28 and 56 days), exposure temperature (300℃, 450℃, 600℃ and 850℃). After specimens were exposed to the high temperatures, residual compressive strength test (RCS) and ultrasonic pulse velocity test (UPV) were carried out on the next day, 35th day after casting and 21-day recurring. The data shows that the UPV decreased for all specimens after exposed to high temperature, and the reduction was more significant for specimens with higher temperature. Internal structural damage caused by the high temperature lowered their densities. In addition, the RCS of normal concrete significantly rose after the concrete exposed to 450℃. The rise was attributed to the evaporation of free water and crystallization water, and then transportation of moisture in concrete. The high temperatures accelerated hydration at the early stage of concrete. Furthermore, the compressive strength at 450℃ decreased for the fly ash concrete. Because fly ash concrete has low permeability and high density, water vapor did not easily dissipate, increasing the pore pressure and eventually leading the production of microcracks. Additionally, insignificant recovery of the UPV and RCS after post-fire-curing existed. Moisture supply with air-curing to continue and expedite the rehydration reactions was not effective.
Ling, Fan, and 范櫺. "Effect of Coarse Aggregate Content on Cracking Shear Strength Of High-Strength Concrete Beams without Shear Reinforcement." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/76407693396442458589.
Full text國立中興大學
土木工程學系所
105
The intention of this study was to investigate the shear behavior of concrete beams without shear reinforcement with different amount of coarse aggregate. A total of 16 beam specimens were made in this study. The compressive strength of concrete were 42 and 50 MPa. The coarse aggregate contents are 750 kg/m3, 850 kg/m3, 950 kg/m3 and 1050 kg/m3 . Two no. 5 bars and three no. 5 bars were used on the longitudinal reinforcement. The compressive strength, coarse aggregate content and axial reinforcement are the main experimental variables. The result shows that : 1. The cracking shear strength of rest beams increases with an increases of coarse aggregate content . 2. The coarse aggregate content dose not have a significant effect on the ultimate shear strength. 3. Beams with coarse aggregate content between 850 kg/m3 and 950 kg/m3 have better crack control ability when the concrete strength is 50 MPa. 4. The stiffness of beam decreases with an increase of coarse aggregate content. The stiffness reaches the largest when the content of coarse aggregate is 750 kg / m3. Increase of longitudinal reinforcement also increases the stiffness
Smit, Martha S. "The effect of mixture proportions on the properties of high strength concrete pavements." Diss., 2015. http://hdl.handle.net/2263/50787.
Full textDissertation (MEng)--University of Pretoria, 2015.
tm2015
Civil Engineering
MEng
Unrestricted
Chang, Feng-Chan, and 張豐展. "Study on the Confining Effect of Reinforced Concrete Columns Using High Strength Materials." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/66940303956414373975.
Full text臺灣大學
土木工程學研究所
98
In common building structures, columns play important roles as vertical and lateral load carrying members. For some columns of high rise buildings, especially those located at the lower parts, the effect of axial load becomes more dominant, causing a huge size in dimension if designed using normal strength materials. However, due to the development of high strength materials, such as high strength concrete and high strength steel, engineers can now yield a more efficient and economical design of columns. Based on the current available research on high strength columns, most of the experimental work was related to the testing of reduced-scale specimens due to the limited testing capacity of the laboratory. This thesis focuses on the experimental study of 5 full-scale specimens (600×600 mm) of high strength columns subjected to quasi-static cyclic loading under constant high axial load, which is made executable because of the availability of MATS (Multi Axial Testing System) in National Center Research on Earthquake Engineering (NCREE), Taiwan. The main purpose of this research is to clarify the size effect, as well as to study the confinement effect and lateral load carrying capacity of reinforced concrete columns with high strength concrete (70, 100 MPa) and reinforced with high yielding strength reinforcement bars, 685 MPa and 785 MPa for column longitudinal and transverse reinforcement bars, respectively. Finally, a verification of the applicability of existing ACI 318-08 code design equation is also evaluated.
Lin, Hua-Xi, and 林華璽. "Effect of Coarse Aggregate Content on Shear Friction Behavior of High Strength Concrete." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/23500644847562091059.
Full textTsai, Yan-Ming, and 蔡彥鳴. "Effect of Coarse Aggregate Size on Shear Friction Behavior of High-Strength Concrete." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/98689092625384424762.
Full textTsai, Wei-Tsung, and 翟慰宗. "Effect of Elevated Temperature on Strength and Ultrasonic Pulse Velocity of Recycled Concrete using Brick Aggregates." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/56896544854499088172.
Full text中原大學
土木工程研究所
99
The purpose of this paper is to investigate the effect on the properties of recycled concrete and mortar with various percentages of natural coarse, fine aggregates and cement replaced by crushed construction brick and tile aggregates. To find the relative compressive strength ratio, the increase in compressive strength between 28-91 days The percentage of decrease in residual strength and the change on compressive strength and ultrasonic pulse velocity (UPV) after subjected to elevated temperatures of recycled concrete and mortar are performed. A simple regression method used to establish the regression equation of compressive strength and temperature of recycled concrete. Experiment results revealed that the development of long-term strength of recycled concrete and mortar is better than that of the natural concrete and mortar. The use of brick coarse and fine aggregate affects the compressive strength slightly. Experiment results revealed that the reduction of UPV of recycled concrete with coarse and fine brick aggregate is higher than that of natural concrete. The UPV of recycled concrete with coarse tile aggregate is higher than that of natural concrete. The use of tile fine aggregate affects the UPV slightly. Regression analysis results revealed that the compressive strength and UPV of recycled concrete with the same coarse brick aggregate replacement had a high relevance. The recycled concrete with various water to cement ratio had a low relevance due to the content of aggregate. The analysis results revealed that the residual strength and residual UPV of recycled concrete with the coarse or fine brick aggregate had a high relevance after elevated temperatures exposure. Experimental results revealed that the compressive strength and UPV of recycled concrete with the same coarse tile aggregate replacement had a high relevance. The replacement of tile affects the regression slightly. The residual strength and residual UPV of recycled concrete with the coarse or fine tile aggregate had a high relevance after elevated temperatures exposure.
fen, Fang sheng, and 方聖棻. "The effect of the lightweight aggregate concrete properties from Sediment at high temperature." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/89063378381137052225.
Full text國立高雄應用科技大學
土木工程與防災科技研究所
94
The merits of lightweight aggregate concrete are having the low rate of thermal conductivity and good condition of fire resistant. Therefore, it is a good aseismatic material. In this research, which used the lightweight aggregate concrete in local reservoir mud and adopted the closle-packed theory from desified mixture design algorithm. In the meanwhile, it discussed the effect of concrete under high temperature between the lightweight aggregate with a grain which density 800 and 1600 kg/m3 and the normal-weight aggregate.The change of water-to-binder ratio respectively in 0.28,0.32 and 0.40 and the amount of mixing water in 170Kg/m3 .Adding the admixtures of fly ash, slg powder and superplasticizer(SP)etc. All these led to the design of the lightweight aggregate concrete to meet the requirement of high proficiency in working. Also, the reduction of cement amount and mixing water met the socioeconomic and durability too.High temperature stove in Germany was used in this investigation. Fixed the rate of heating in 4℃/min and accorded to the three types of temperature respectively at 250℃, 500℃and 750℃.Furthermore, two types of time delay respectively in 1 and 2 hours used to test the high temperature delay.It was Compared with the room temperature(25℃) and confer the change of contracture nature assisting the SEM testing, and the observation of the change of mico-structure after high temperature. After high temperature, the lightweight aggregate concrete still remained high resistance of strength remanent rate between 56%and 99%. The electrical resistanty remanent rate was between 40% and 93% and the ultrasonic pulse velocity remanent rate was between 45% and 86%. The crack width was between 86μm and 398μm, but it was corroded by the sodium sulfate. After heating, the temperature of lightweight aggregate concrete was low and its heat insulation was fine. It showed that the lightweight aggregate concrete is the superiority quality after high temperature. As a result, it is favorable to the fire resistance of buildings. But need to pay attention to the durability problem was made by micro-cracks.
Horng, Gwo-Shyang, and 洪國祥. "Study on the Effect of High-Temperature Steam Curing on Taiwan Concrete(TAICON)." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/05119369277207166374.
Full text國立交通大學
土木工程系
87
The objective of this study is to substitute a portion of cement with fly ash, add appropriate amounts of superplasticizer, and then to study how the resultant concrete reacts under high-temperature steam curing to determine the best high-temperature steam curing model in hopes of using the results of the experiment to produce medium strength, high performance Taiwan concrete (Taicon) suitable for use by the local construction industry. The results of this study show that high-temperature steam curing produces a slowing down of growth or no growth at all in later-age strengths, especially after undergoing 16 hours of catalytic time at temperatures of 180°C. High-temperature steam curing also reduces dry shrinkage and weight change. Early age strength and 91st day strength are virtually the same. High-temperature steam curing has lower Ec than that of standard curing. Curing temperatures of 180°C are best, while 150°C is second best, and 120°C is least ideal. Curing for 16 hours has the best effect-16 hours of catalytic time is superior to 8 hours, which is superior to 4 hours, which is superior to 2. The best curing model is as follows: Curing temperatures of 180°C、8 hours of presetting time and 16 hours of catalytic time. Early-age strength is about 180% of that of the first 28 days of standard curing methods. Early-age strength is virtually identical to 91st day strength.
Sheu, Shiou Haur, and 許修豪. "Effect of different cooling method and re-curing method on strength recovery of concrete suffering elevated temperature." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/61525513751783620614.
Full text國立交通大學
土木工程系
87
The compressive strength of concrete was lost significantly at high temperature, and might affect the safety of the structure. But partial recovery in strength may occur by appropriate re-curing. This study is aimed at the investigation of the strength recovery of Normal Strength Concrete and High Performance Concrete after suffering elevated temperature with different cooling method and re-curing method. This study is devoted to investigate the effects of re-curing method. The major experimental parameters include cooling method (natural cooling, forced cooling), re-curing method (air curing, intermittent water curing, sustained water curing), and curing time (1, 7, 28, 91 days). Result shows that intermittent water curing can get the best recovery strength.
Chen, Yen-Jui, and 陳彥睿. "Study of Mechanical Behavior of High Strength Fiber Reinforced Concrete Filled with Steel Tube at Elevated Temperature." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/15002564513978334532.
Full textKuo, Yao-Jen, and 郭耀仁. "Study of the Mechanical Properties and Confinement Effect of High Strength Steel Fiber Reinforced Concrete." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/20414469715840489155.
Full text國立臺灣大學
土木工程學研究所
100
From 1988 to 1992, the Japanese government carried on a five-year national project, New RC Project, to substantially increase the strength of the construction materials of the reinforced concrete for high rise buildings. The concrete strength rises from 40 MPa to 120 MPa, and the yielding strength of steel bar rises from 420 MPa to 685 MPa. Up to 2007, Janpan already has more than 500 New RC buildings. Due to brittleness of high strength concrete, much more confinement is needed to improve the ductility and satisfy seismic requirements for high strength reinforced column, particularly under high axial loading demands. Furthermore, early cover spalling trigs substantial compressive strength loss and thus sudden failure occurs. Many studies show that addition of steel fibers can not only effectively prevent the early cover spalling, but also increase the toughness and ductility of high-strength concrete. This study investigates the mechanical properties and confinement effect of high-strength steel fiber reinforced concrete. The objective is to understand the relationship between the toughness and the volume fraction of steel fibers of high-strength steel fiber reinforced concrete, and proposed the regressive formulation of the toughness of high strength steel fiber reinforced concrete. The confinement efficiency provided by steel fibers or stirrups is also proposed by the regressive formulation of the toughness. In addition, the shrinkage experiments, including measurement of autogenous shrinkage and total drying shrinkage, are conducted to verify the volume stability of high-strength steel fiber reinforced concrete.
Vidya, Sagar R. "Concrete Fracture And Size Effect - Experimental And Numerical Studies." Thesis, 2008. http://hdl.handle.net/2005/912.
Full textChung-Chin, Cheng, and 陳忠慶. "Effect of Silica Fume on the Bond Strength of Tensile Deformed Bars of High-Performance Concrete." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/39373072748494893357.
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