scholarly journals INFLUENCE OF COARSE AGGREGATE AND MIX PROPORTION TO DRYING SHRINKAGE OF CONCRETE

2011 ◽  
Vol 76 (668) ◽  
pp. 1729-1735
Author(s):  
Yoshiaki OHNO ◽  
Yoshihiro MASUDA ◽  
Tadatsugu KAGE
Keyword(s):  
Coarse Aggregate ◽  
Drying Shrinkage ◽  
Mix Proportion

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.

scholarly journals Use of Recycled Tyre Rubber in Non-structural Concrete

2018 ◽  
Vol 203 ◽  
pp. 06001
Author(s):  
Muhammad Bilal Waris ◽  
Hussain Najwani ◽  
Khalifa Al-Jabri ◽  
Abdullah Al-Saidy
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Coarse Aggregate ◽  
Partial Replacement ◽  
Fine Aggregate ◽  
Structural Concrete ◽  
Cement Ratio ◽  
Mix Proportion ◽  
Water To Cement Ratio ◽  
Concrete Blocks

To manage tyre waste and conserve natural aggregate resource, this research investigates the use of waste tyre rubber as partial replacement of fine aggregates in non-structural concrete. The research used Taguchi method to study the influence of mix proportion, water-to-cement ratio and tyre rubber replacement percentage on concrete. Nine mixes were prepared with mix proportion of 1:2:4, 1:5:4 and 1:2.5:3; water-to-cement ratio of 0.25, 0.35 and 0.40 and rubber to fine aggregate replacement of 20%, 30% and 40%. Compressive strength and water absorption tests were carried out on 100 mm cubes. Compressive strength was directly proportional to the amount of coarse aggregate in the mix. Water-to-cement ratio increased the strength within the range used in the study. Strength was found to be more sensitive to the overall rubber content than the replacement ratio. Seven out of the nine mixes satisfied the minimum strength requirement for concrete blocks set by ASTM. Water absorption and density for all mixes satisfied the limits applicable for concrete blocks. The study indicates that mix proportions with fine to coarse aggregate ratio of less than 1.0 and w/c ratio around 0.40 can be used with tyre rubber replacements of up to 30 % to satisfy requirements for non-structural concrete.

scholarly journals Durability and Shrinkage Characteristics of Self-Compacting Concretes Containing Recycled Coarse and/or Fine Aggregates

2015 ◽  
Vol 2015 ◽  
pp. 1-18 ◽  
Author(s):  
Mehmet Gesoglu ◽  
Erhan Güneyisi ◽  
Hatice Öznur Öz ◽  
Mehmet Taner Yasemin ◽  
Ihsan Taha
Keyword(s):  
Coarse Aggregate ◽  
Gas Permeability ◽  
Drying Shrinkage ◽  
Recycled Aggregate ◽  
Fine Aggregate ◽  
Restrained Shrinkage ◽  
Durability Properties ◽  
Recycled Fine Aggregate ◽  
Restrained Shrinkage Cracking ◽  
Fine Aggregates

This paper addresses durability and shrinkage performance of the self-compacting concretes (SCCs) in which natural coarse aggregate (NCA) and/or natural fine aggregate (NFA) were replaced by recycled coarse aggregate (RCA) and/or recycled fine aggregate (RFA), respectively. A total of 16 SCCs were produced and classified into four series, each of which included four mixes designed with two water to binder (w/b) ratios of 0.3 and 0.43 and two silica fume replacement levels of 0 and 10%. Durability properties of SCCs were tested for rapid chloride penetration, water sorptivity, gas permeability, and water permeability at 56 days. Also, drying shrinkage accompanied by the water loss and restrained shrinkage of SCCs were monitored over 56 days of drying period. Test results revealed that incorporating recycled coarse and/or fine aggregates aggravated the durability properties of SCCs tested in this study. The drying shrinkage and restrained shrinkage cracking of recycled aggregate (RA) concretes had significantly poorer performance than natural aggregate (NA) concretes. The time of cracking greatly prolonged as the RAs were used along with the increase in water/binder ratio.

Correlation Research of Concrete Mix Proportion on Cement Dosage in Coarse Aggregate

2014 ◽  
Vol 556-562 ◽  
pp. 692-695
Author(s):  
Zhang Bo
Keyword(s):  
Cost Reduction ◽  
High Speed ◽  
Coarse Aggregate ◽  
Social Economy ◽  
Project Design ◽  
Mixing Ratio ◽  
Project Cost ◽  
Mix Proportion ◽  
Concrete Mix ◽  
Selection Of

Along with the high-speed development of social economy in our country, the country invests more in infrastructure construction. The ratio of concrete in coarse aggregate has great impact on engineering quality. If there are any proportion problems, a certain degree of engineering accidents and sometimes even devastating accidents can be caused. This article studies the correlation between concrete proportioning and cement dosage in coarse aggregate through practices, discovers the importance of reasonable selection of coarse aggregate in economic cement mixing ratio configuration process, and realizes the implementation of project cost reduction in project design.

Experimental Research on Pore Structure of RCA and its Impact on Drying Shrinkage

2011 ◽  
Vol 335-336 ◽  
pp. 1141-1144 ◽  
Author(s):  
Yun Xiang He
Keyword(s):  
Fly Ash ◽  
Pore Structure ◽  
Drying Shrinkage ◽  
Recycled Aggregate ◽  
Structure Theory ◽  
Replacement Rate ◽  
Pore Characteristics ◽  
Cement Ratio ◽  
Mix Proportion ◽  
The Impact

Pore structure is one of the main influencing factors of materials drying shrinkage. C30 natural mix proportion is used as reference, the impact of replacement rate of recycled aggregate, the mixing amount of fly ash, water reducer, expansion agent and water-cement ratio on recycled aggregate concrete’s porosity and pore characteristics was studied. Based on the pore structure theory, the influence of porosity and pore characteristics on recycled aggregate concrete’s drying shrinkage is analyzed.

Experimental Research on Physical and Mechanical Properties of Steel Fiber High-Strength Concrete

2010 ◽  
Vol 168-170 ◽  
pp. 1061-1064 ◽  
Author(s):  
Yu Dong Wang ◽  
Xiao Chun Fan
Keyword(s):  
High Strength Concrete ◽  
Bending Strength ◽  
Steel Fiber ◽  
Mechanical Performance ◽  
Physical And Mechanical Properties ◽  
Drying Shrinkage ◽  
High Strength ◽  
Engineering Practice ◽  
Strength Concrete ◽  
Mix Proportion

Based on experiment, the mix proportion matching with the design and construction requirements is obtained. It meets with the requirement of pump structure on the basis of meeting the strength requirement. On this basis, the basic physical and mechanical performance is studied and the conclusion is that steel fiber high-strength concrete has excellent resistance to splitting, bending and drying shrinkage. The splitting strength and bending strength of steel fiber high-strength concrete named CF60-2 is respectively 38.7% and 56.8% higher than that of plane concrete named C60. The drying shrinkage rate of CF60-2 is 45.5% lower than that of C60 in three days. The results have an important guiding significance to steel fiber high-strength concrete in theoretical and engineering practice.

scholarly journals Properties of concrete containing recycled concrete aggregate of preserved quality

2021 ◽  
Author(s):  
Jonathan Andal
Keyword(s):  
Coarse Aggregate ◽  
Drying Shrinkage ◽  
Recycled Concrete ◽  
Partial Replacement ◽  
Concrete Aggregate ◽  
Recycled Concrete Aggregate ◽  
Salt Scaling ◽  
Concrete Properties ◽  
Comparable Quality ◽  
Scaling Resistance

Today, there is a growing need for the implementation of sustainability in construction. Continuous construction and rehabilitation projects have begun to deplete virgin aggregate sources. The use of recycled concrete aggregate (RCA) in concrete has been regarded as a sustainable and environmentally friendly alternative aggregate source. This thesis focuses on producing RCA of preserved quality through the use of a new protocol aimed at maintaining the original properties of returned-to-plant concrete. The performance of RCA with preserved quality and commercially available RCA when used in concrete was compared. Different concrete properties were evaluated including the fresh, hardened and durability characteristics. Results showed that the RCA with preserved quality performed better in many categories, including strength, drying shrinkage and salt scaling resistance compared to the commercial RCA. The use of 30% preserved-quality RCA as partial replacement of coarse aggregate produced concrete of comparable quality to that produced with virgin aggregate.

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