Relationship between Drying Shrinkage Strain of Concrete and Quality of Coarse Aggregate

2020 ◽  
Vol 58 (3) ◽  
pp. 223-228
Author(s):  
H. Yamada ◽  
H. Katahira ◽  
H. Watanabe
Keyword(s):  
Coarse Aggregate ◽  
Drying Shrinkage ◽  
Shrinkage Strain

scholarly journals Concrete with Reused Concrete Sand

2019 ◽  
Vol 8 (6) ◽  
pp. 4868-4873
Keyword(s):  
Elastic Modulus ◽  
Compression Strength ◽  
Drying Shrinkage ◽  
Shrinkage Strain ◽  
Ordinary Concrete ◽  
Mixed Concrete

This paper examines the impacts of substitution of reused concrete sand (RCS) with sands, on the new and hardened physiognomies of concrete. the property of RCS blended concrete was examined and likened with ordinary concrete of 40 MPa compression strength. the physiognomies of RCS concrete vary from ordinary concrete arranged with characteristic sand, as an outcome of the quality of connected mortar, old cement glue, and more fines. the outcomes demonstrate that the RCS concrete demonstrations tantamount workability in contrast with ordinary concrete. the mechanical physiognomies (compressive, flexure, split tensile and elastic modulus) of concrete developed with RCS was lower in compression to ordinary concrete however worthy up to 60percentage RCS in the blend. The drying shrinkage strain of 100percentage RCC mixed concrete at twenty-eight days was watched twice in compression to controlled concrete and it demonstrated more abrasion value in that comparison and furthermore concrete developed with 100 percent RCS indicated 41percentage and 11.3percentage lower in sorption value at ahead of schedule and later age organize individually in that examination.

scholarly journals INFLUENCE OF SUPERPLASTICIZER AND VARYING AGGREGATE SIZE ON THE DRYING SHRINKAGE AND COMPRESSIVE STRENGTH OF LATERISED CONCRETE

2017 ◽  
Vol 36 (3) ◽  
pp. 734-739
Author(s):  
F Falade ◽  
B Ukponu ◽  
OJ Ugbaja
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Aggregate Size ◽  
Drying Shrinkage ◽  
Shrinkage Strain ◽  
Maximum Compressive Strength ◽  
Control Samples

This paper presents the results of the study on the influence of superplasticizer and varying aggregate size on the drying shrinkage and compressive strength of laterised concrete. Four different samples of laterised concrete were made from prescribed mix ratio of 1:1:2 which include; two control specimens made with different coarse aggregate sizes (12.5mm and 19mm) and another two specimens that have the same composition as the control samples with addition of superplasticizer (Conplast 430). The compressive strength and drying shrinkage were determined at the curing periods (7, 14, 21 and 28 days). The results showed that specimens made with 12.5mm diameter coarse aggregate and superplasticizer developed a maximum compressive strength (44N/mm2) at 28th day. This maximum compressive strength was 29.6%, 31.8% and 4.6% greater than the compressive strength developed by the control specimens and specimens made with 19mm diameter coarse aggregate and superplasticizer. Specimens made with 19mm diameter coarse aggregate and superplasticizer developed the minimum shrinkage strain (1.48⨯0-3) at 90th day. This value was 17%, 13.5% and 8.1% less than shrinkage strain of the control specimens and specimen made with 12.5mm coarse aggregate size and superplasticizer. The addition of superplasticizer increased the compressive strength and reduced the shrinkage strain of all specimens; while increase in coarse aggregate size reduced both compressive strength and drying shrinkage.  http://dx.doi.org/10.4314/njt.v36i3.11

Study on Strength and Durability of Concrete Containing Recycled Coarse Aggregate Manufactured with Various Method

2011 ◽  
Vol 287-290 ◽  
pp. 1015-1018 ◽  
Author(s):  
Hong Zhu Quan
Keyword(s):  
Modulus Of Elasticity ◽  
Coarse Aggregate ◽  
Drying Shrinkage ◽  
Recycled Aggregate ◽  
Test Results ◽  
Recycled Coarse Aggregate ◽  
Concrete Mixtures ◽  
Strength And Durability ◽  
Durability Of Concrete

This paper presents the results of experimental study on the effects of adhered mortar content on strengths and durability of concrete. Compressive, tensile and shear strengths, modulus of elasticity, drying shrinkage and carbonation were tested on concrete mixtures with the water cement ratio of 0.43, 0.50 and 0.60 using 3 kinds recycled coarse aggregate and a riversand. The test results of concrete indicated higher compressive, tensile amd shear strengths and higher modulus of elasticity for concrete using recycled corase aggregate with lower adhered mortar content, lower absorption and higher specific gravity. Recycled aggregate with higher adhered mortar content also showed significunt adverse effects on drying shrinkage and carbonation. In conclusion, the upper limit of adhered mortar content of coarse recycled aggregate to keep up the quality of aggregate and concrete equal to natural coarse aggregate and those concrete is considered to be 15%.

scholarly journals INFLUENCE OF QUALITY OF COARSE AGGREGATE ON DRYING SHRINKAGE OF CONCRETE

2011 ◽  
Vol 65 (1) ◽  
pp. 261-267
Author(s):  
Masumi INOUE ◽  
Shintaro YAMASAKI ◽  
Heizaburo IGARI ◽  
Kaneyoshi OKADA
Keyword(s):  
Coarse Aggregate ◽  
Drying Shrinkage

scholarly journals Study on the Effect of Recycled Coarse Aggregate on the Shrinkage Performance of Green Recycled Concrete

2021 ◽  
Vol 13 (23) ◽  
pp. 13200
Author(s):  
Yang Yu ◽  
Peihan Wang ◽  
Zexin Yu ◽  
Gongbing Yue ◽  
Liang Wang ◽  
...  
Keyword(s):  
Primary Particle ◽  
Coarse Aggregate ◽  
Cementitious Material ◽  
Recycled Concrete ◽  
Low Carbon ◽  
Replacement Ratio ◽  
Recycled Coarse Aggregate ◽  
Shrinkage Property ◽  
Low Carbon Emission

Shrinkage property is a significant indicator of the durability of concrete, and the shrinkage of green recycled concrete is particularly problematic. In this paper, construction waste was crushed and screened to generate simple-crushed recycled coarse aggregate (SCRCA). The SCRCA was then subjected to particle shaping to create primary particle-shaped recycled coarse aggregate (PPRCA). On this basis, the PPRCA was particle-shaped again to obtain the secondary particle-shaped recycled coarse aggregate (SPRCA). Under conditions where the dosage of cementitious material is 300 kg/m3 and the sand rate is 38%, a new high-belite sulphoaluminate cement (HBSAC) with low carbon emission and superior efficiency was used as the basic cementitious material. Taking the quality of recycled coarse aggregate (SCRCA, PPRCA, and SPRCA) and the replacement ratio (25%, 50%, 75%, and 100%) as the influencing factors to prepare the green recycled concrete, the workability and shrinkage property of the prepared concrete were analyzed. The results show that the water consumption of green recycled concrete decreases as the quality of the recycled coarse aggregate (RCA) increases and the replacement ratio decreases, provided that the green recycled concrete achieves the same workability. With the improvement of RCA quality and the decrease of replacement ratio, the shrinkage of recycled concrete decreases. The shrinkage performance of green recycled concrete configured with the SPRCA completely replacing the natural coarse aggregate (NCA) is basically the same as that of the natural aggregate concrete (NAC).

Drying Shrinkage of Concrete Affected by Content of Stone Powder in Proto-Machine-Made Sand

2010 ◽  
Vol 152-153 ◽  
pp. 1176-1179 ◽  
Author(s):  
Feng Lan Li ◽  
Qian Zhu
Keyword(s):  
Compressive Strength ◽  
Standard Method ◽  
Structural Engineering ◽  
Drying Shrinkage ◽  
Shrinkage Strain ◽  
Test Results ◽  
Similar Test ◽  
Mix Proportion ◽  
Compressive Strength Of Concrete ◽  
Main Factor

To improve the application of the new proto-machine-made sand in structural engineering, tests are carried out to study the drying shrinkage of concrete affected by stone powder in proto- machine-made sand. The target cubic compressive strength of concrete is 55 MPa, the main factor varied in mix proportion of concrete is the contents of stone powder by mass of proto-machine-made sand from 3 % to 16 %. The drying shrinkage strains of concrete are measured by the standard method at the ages of 1 d, 3 d, 7 d, 14 d, 28 d, 60 d, 90 d, 120 d, 150 d and 180 d. Based on test results, the drying shrinkage of concrete affected by the contents of stone powder in proto-machine-made sand is analyzed and compared with that of similar test of concrete with traditional machine-made sand, which shows that there is the optimum content of stone powder resulting in the lower drying shrinkage of concrete. The formula for predicting drying shrinkage strain of concrete is proposed.

Alkali-Activated EAF Reducing Slag as Binder for Concrete

2013 ◽  
Vol 723 ◽  
pp. 580-587
Author(s):  
Wen Huan Zhong ◽  
Tung Hsuan Lu ◽  
Wei Hsing Huang
Keyword(s):  
Portland Cement ◽  
Drying Shrinkage ◽  
Portland Cement Concrete ◽  
Steel Making ◽  
Chemical Content ◽  
Alkaline Activator ◽  
Furnace Slag ◽  
Alkali Activated ◽  
Better Than

Electric arc furnace (EAF) reducing slag is the by-product of EAF steel-making. Currently, reducing slag is considered a waste material by the industry in Taiwan. Since the chemical content of reducing slag is similar to blast furnace slag (BFS), it is expected that reducing slag exhibits a similar pozzolanic effect as the BFS. This study used alkaline activator consisting of sodium silicate and sodium hydroxide to improve the activity of reductive slag so as to replace Portland cement as binder in concrete. Some BFS was used to blend with the reducing slag to enhance the binding quality of alkali-activated mixes. The results show that a blend of 50% BFS and 50% reducing slag can be activated successively with alkali. Also, the sulfate resistance of concrete made with alkali-activated EAF reducing slag is found to be better than that of concrete made with portland cement, while the drying shrinkage of alkali-activated EAF reducing slag concrete is greater than that of portland cement concrete.

scholarly journals Experimental Study on Durability Improvement of Fly Ash Concrete with Durability Improving Admixture

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Hong-zhu Quan ◽  
Hideo Kasami
Keyword(s):  
Fly Ash ◽  
Experimental Studies ◽  
Drying Shrinkage ◽  
Replacement Ratio ◽  
Fly Ash Concrete ◽  
Air Content ◽  
Carbonation Resistance ◽  
Binder Ratio ◽  
Water Binder Ratio

In order to improve the durability of fly ash concrete, a series of experimental studies are carried out, where durability improving admixture is used to reduce drying shrinkage and improve freezing-thawing resistance. The effects of durability improving admixture, air content, water-binder ratio, and fly ash replacement ratio on the performance of fly ash concrete are discussed in this paper. The results show that by using durability improving admixture in nonair-entraining fly ash concrete, the compressive strength of fly ash concrete can be improved by 10%–20%, and the drying shrinkage is reduced by 60%. Carbonation resistance of concrete is roughly proportional to water-cement ratio regardless of water-binder ratio and fly ash replacement ratio. For the specimens cured in air for 2 weeks, the freezing-thawing resistance is improved. In addition, by making use of durability improving admixture, it is easier to control the air content and make fly ash concrete into nonair-entraining one. The quality of fly ash concrete is thereby optimized.

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