Experimental Study on Compressive Strength and Flexural Strength of Combined Aggregate Concrete

2014 ◽  
Vol 1065-1069 ◽  
pp. 1899-1902
Author(s):  
Yan Kun Zhang ◽  
Yu Cheng Wang ◽  
Xiao Long Wu

In this article, the flexural strength of combined aggregate concrete with four kinds of water-cement ratio (0.3,0.35.0.4, 0.45), and six ceramsite replace rate (0%, 20%, 40%, 60%, 80%, 60%) are studied with comprehensive test method. Experiment shows that the ceramsite replace rate of combined aggregate has greater influence on the flexural strength than the water-cement ratio. The flexural strength increases with the increasing of compressive strength, and the formula of the flexural strength and compressive strength of combined aggregate concrete is given.

2014 ◽  
Vol 887-888 ◽  
pp. 814-818
Author(s):  
Li Xue Wang ◽  
Xiao Ting Shan ◽  
Yu Qing Zhang ◽  
Chun Sheng Li ◽  
Zai Xing Wang ◽  
...  

In order to research the changes of concrete properties in freeze-thaw environment, five concrete samples with water-cement ratio respectively equal to 0.60, 0.65, 0.70, 0.75 and 0.80 were tested in freeze-thaw environment according to GB/T50082-2009 concrete rapid freeze-thaw cycles test method. Five samples were carried out 0, 25, 50, 75, 100 times faster freeze-thaw cycles test. With the increasing number of freeze-thaw cycles, the concrete relative dynamic modulus of elasticity loss rises, the compressive strength drops, and the carbonation depth increases. The greater the water-cement ratio of concrete specimens with freeze-thaw cycles, the greater the degree of damage increases.


2019 ◽  
Vol 280 ◽  
pp. 04010
Author(s):  
Nursiah Chairunnisa ◽  
Arie Febry Fardheny

This experimental study is focused on the performance of appropriate grout/mortar for pre-placed aggregate concrete (PAC) incorporating superplasticizer in the mortar mixture regarding the flowability and strength of grout or mortar. Twenty-one samples of specimens were prepared. The parameter tests consist of water-cement ratios, cement sand ratios and variation dosages of superplasticizer. To examine the flowability/fluidity of grout or mortar, the flow cone test was applied. The flow cone test result indicated that there were three proportional grout that can meet the requirement for fluidity according to ASTM C-939. The compressive strength of specimens was tested. It was concluded that the composition of grout with containing the percentage of 0.7% by weight of cement of superplasticizer as chemical admixtures at a water-cement ratio of 0.6 and a cement-sand ratio of 0.5 is the proper composition of grout for pre-placed aggregate concrete (PAC).


2008 ◽  
Vol 385-387 ◽  
pp. 381-384 ◽  
Author(s):  
Wei Wang ◽  
Hua Ling ◽  
Xiao Ni Wang ◽  
Tian Xia ◽  
Da Zhi Wang ◽  
...  

With the increase in the use of recycled aggregate concrete (RAC), it is necessary to clearly understand its behavior and characteristics. In this paper, experimental study on compressive strength of RAC with same water/cement ratio is conducted. Firstly, influence of recycled coarse aggregate contents on cube compressive strength of RAC is studied. Secondly, experiment on time-dependent strength developing process of RAC is conducted with different solidification ages. Finally, based on above experimental investigations, empirical formula for compress strengths of RAC with different ages is presented. The result of this paper is helpful to theoretical analysis and practical engineering design of RAC structures.


2018 ◽  
Vol 8 (8) ◽  
pp. 1324 ◽  
Author(s):  
How-Ji Chen ◽  
Chung-Hao Wu

Expanded shale lightweight aggregates, as the coarse aggregates, were used to produce lightweight aggregate concrete (LWAC) in this research. At the fixed water-cement ratio, paste quantity, and aggregate volume, the effects of various aggregate gradations on the engineering properties of LWAC were investigated. Comparisons to normal-weight concrete (NWC) made under the same conditions were carried out. From the experimental results, using normal weight aggregates that follow the specification requirements (standard gradation) obtained similar NWC compressive strength to that using uniform-sized aggregates. However, the compressive strength of LWAC made using small uniform-sized aggregates was superior to that made from standard-grade aggregates. This is especially conspicuous under the low water-cement ratio. Even though the workability was affected, this problem could be overcome with developed chemical additive technology. The durability properties of concrete were approximately equal. Therefore, it is suggested that the aggregate gradation requirement of LWAC should be distinct from that of NWC. In high strength LWAC proportioning, following the standard gradation suggested by American Society for Testing and Materials (ASTM) is optional.


2013 ◽  
Vol 830 ◽  
pp. 435-438
Author(s):  
Hong Xia Wang ◽  
Bo Liu ◽  
Kuang Ping Yuan ◽  
Wu Biao Duan ◽  
Fei Hua Yang ◽  
...  

The paper introduces a kind of foaming plaster with main raw material of α- gypsum, which is produced by utilizing the chemical reaction principles H2O2 was decomposed. Meanwhile,study the changes of density,flexural strength and compressive strength of plaster material performance with the additives in different ratio. The result showed that water-cement ratio, H2O2 foaming agent and water temperature all affect the performance of the foaming plaster.


Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 590 ◽  
Author(s):  
Zengshun Chen ◽  
Yemeng Xu ◽  
Jianmin Hua ◽  
Xu Wang ◽  
Lepeng Huang ◽  
...  

Graphene oxide (GO) has been widely used as an additive due to its numerous unique properties. In this study, the compressive strength, flexural strength and elasticity modulus of concrete containing 0.02 wt%, 0.05 wt % and 0.08 wt % GO, and its dry shrinkage performance have been experimentally investigated. After the sample preparation, apparatus for compression test and flexural test were used to test the relevant properties of concrete containing GO. The dial indicators were used to measure the shrinkage of samples. The results indicate that GO can considerably improve the compressive strength, flexural strength, and elasticity modulus of concrete at the concrete age of 28 days by 4.04–12.65%, 3.8–7.38%, and 3.92–10.97%, respectively, which are substantially smaller than the increment at the age of 3 d by 5.02–21.51%, 4.25–13.06%, and 6.07–27.45% under a water-cement ratio of 0.35. It was also found that GO can increase the shrinkage strain of concrete. For example, at the age of 60 days, 0.02 wt%, 0.05 wt% and 0.08 wt% GO can increase the shrinkage strain of ordinary concrete by 1.99%, 5.79% and 7.45% respectively under a water-cement ratio of 0.49. The study has advanced our understanding on mechanical and shrinkage behavior of concrete containing GO.


2017 ◽  
Vol 25 (1) ◽  
pp. 77-86 ◽  
Author(s):  
Tsai-Lung Weng ◽  
Wei-Ting Lin ◽  
Cheng-Hao Li

The repair of damaged structures is a complicated problem in the construction industry and it is no uniform standard for evaluating the effectiveness of repair materials. Two different redispersible polymer powders, ethylene vinyl acetate (EVA) and polyvinyl acetate-vinyl carboxylate (VA/VeoVa), were added in the repair mortars with two water-cement ratios and three polymer-cement ratios. The effectiveness of repair materials was evaluated according to the physical, mechanical properties and micrographs. Testing program includes setting time, drying shrinkage, thermal expansion, compressive strength, tensile strength, flexural strength, bond strength, X-ray diffraction analysis, scanning electron microscopy observation. Test results show that the specimens with VA/VeoVa and w/c of 0.5 have highest compressive strength, tensile strength, flexural strength and bond strength. The specimen with EVA also has higher strength than control one at the age of 28 days. The drying shrinkage deformation of VA/VeoVa specimen is close to the control one. The specimens with VA/VeoVa have lower thermal expansion than EVA specimen when the water-cement ratio is 0.5 and there is no difference between EVA and VA/VeoVa specimens for the water-cement ratio of 0.6. The micrographs show that adding polymer powder can reduce the pore and improve the durability.


2020 ◽  
Vol 862 ◽  
pp. 135-139
Author(s):  
Dhabit Zahin Alias Tudin ◽  
Ahmad Nurfaidhi Rizalman

In this study, crumb rubber was used to partially replaced fine aggregate in mortar mixture by 5, 10, 15 and 20 volume percentage (vol%) with untreated and NaOH-treated crumb rubber. There were three (3) different water-cement ratio used which are 0.45, 0.50 and 0.55. Thus, the total number of mixtures was 27. The mortars were tested for flowability, compressive strength, flexural strength and density. Based on the results, higher water cement ratio and percentage of crumb rubber replacement increased the flowability but lowered the density, compressive strength and flexural strength of the rubberized mortar. It was also discovered that the significant effect of water-cement ratio on the fresh and hardened properties of the rubberized mortar was due to the water content in the mixture. Meanwhile, the use of NaOH as treatment to crumb rubber improved the flowability, compressive strength and flexural strength of the rubberized mortar.


2014 ◽  
Vol 912-914 ◽  
pp. 131-135
Author(s):  
Xiang Ping Fu ◽  
Xiao Xue Liu ◽  
Yi Ze Sun ◽  
Pei Huang ◽  
Yu Chen Li ◽  
...  

The experiment studies how the freeze-thaw cycles influence concrete compressive strength and elasticity modulus with different water-cement ratio under the air-entraining agent and zero of that value respectively. It can be found that modulus of elasticity and compressive strength of the concrete specimen reduced significantly when there is air-entraining agent; the durability of freeze-thaw resistance, however, makes great improvement; as the cement increases, both of them improves effectively. Through the comparison of concrete compressive strength and elastic modulus with different water-cement ratio and air-entraining agent, the optimal water-cement ratio and air-entraining agent were determined. The results of experiment can be used in concrete engineering design in severe cold area.


2014 ◽  
Vol 507 ◽  
pp. 406-409
Author(s):  
Hua Cheng Nie ◽  
Yan Kun Zhang ◽  
Biao Zhang ◽  
Shao Jie Shen ◽  
Jiang Xing Fan

Base on the experiment, the cube compressive strength of the combined aggregate concrete is studied in the paper. The results show that the strength of combined aggregate concrete increases with the decreasing amounts of lightweight aggregate, and the water-cement ratio and the replacement ratio of lightweight aggregate are the main factor on the strength of combined concrete. According to the experiment results, the formula of the compressive strength of combined concrete is given.


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