scholarly journals EFFECTS OF MIX PROPORTION AND COARSE AGGREGATE ON TENSILE ANISOTROPY OF CONCRETE : Effects of Bleeding on the Internal Structure of Concrete (II)

1975 ◽  
Vol 235 (0) ◽  
pp. 1-8
Author(s):  
TOMOZO SOSHIRODA
Keyword(s):  
Internal Structure ◽  
Coarse Aggregate ◽  
Mix Proportion

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.

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.

Effect of Mixing Steel Dust and Shred-Like Steel Fibres on the Properties of Concrete

2019 ◽  
Vol 7 (1) ◽  
pp. 24-29
Author(s):  
A. Ajwad ◽  
N. Khadim ◽  
Abdullah ◽  
U. Ilyas ◽  
M. U. Rashid ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Coarse Aggregate ◽  
Strength Test ◽  
Hardened Concrete ◽  
Normal Concrete ◽  
Steel Fibres ◽  
Coarse Aggregates ◽  
Mix Proportion ◽  
Steel Dust

In this research, fine and coarse aggregates present in the concrete are replaced with steel dust and shred-like steel fibres, respectively in different ratios and its effect on the properties of concrete is studied. Eight batches of concrete were mixed, each with the mix proportion of 1:2:4 and water cement ratio of 0.52. Batch A was of normal concrete. In batches B, C, and D, 5%, 10%, and 15% of sand was replaced with steel dust. In batches, E, F, and G, 2%, 5%, and 8% of coarse aggregate were replaced with steel fibres. In the last batch H, both 5% of sand and 5% of coarse aggregate were replaced with steel fine and steel fibres respectively. British as well as American standards were followed during the research. Slump test was performed in a fresh state of each mix to find the effect of these replacements on workability. 12 cubes of 150mm x 150mm x 150mm for compressive strength test and 12 cylinders of 150mm diameter and 300mm height of each, for tensile strength test were made for each batch to check these strength after 3, 7, 14, 28 days. It was found that the workability of fresh concrete decreases while density of fresh as well as hardened concrete increases with these replacements. It also results in an increase in initial compressive strength and a decrease in final compressive strength as compared to those of normal concrete. As far as tensile strength is concerned an increase in initial as well as final strength was observed.

Experimental Study on Producing Concrete Hollow Block with Mining Slag

2011 ◽  
Vol 261-263 ◽  
pp. 820-823 ◽  
Author(s):  
Yu Ze Tian
Keyword(s):  
Experimental Study ◽  
Mine Tailings ◽  
Coarse Aggregate ◽  
National Standards ◽  
Iron And Steel ◽  
Mix Proportion ◽  
Iron Mine ◽  
Sample Test ◽  
Waste Rocks ◽  
Hollow Block

The experiments of compressive strength about maix proportion of concrete are repeatedly done, adopting orthogonal experimental method. In this experiment, dry separation waste rocks and mine tailings in mining slag of Qidashan Iron Mine which is subsidiary company of Anshan Iron and Steel Corporation are used instead of traditional fine and coarse aggregate concretes. Then the optimized mix proportion is determined to make the concrete small hollow blocks. Sample test shows that it is feasible to make load bearing concrete small hollow blocks which can meet national standards.

scholarly journals Mixture Proportion Design Method of Steel Fiber Reinforced Recycled Coarse Aggregate Concrete

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 375 ◽  
Author(s):  
Danying Gao ◽  
Lijuan Zhang ◽  
Michelle Nokken ◽  
Jun Zhao
Keyword(s):  
Coarse Aggregate ◽  
Steel Fiber ◽  
Design Method ◽  
Target Strength ◽  
Test Results ◽  
Fiber Reinforced ◽  
Aggregate Concrete ◽  
Recycled Coarse Aggregate ◽  
Mix Proportion ◽  
Fiber Characteristic

Steel fiber reinforced recycled coarse aggregate concrete (SFRCAC) is an impact minimisation building material. Mixture proportion design method of SFRCAC is developed in this paper to obtain concrete with target strength and workability, which can be used in structural members. Four key parameters of mixture proportioning, steel fiber content, water-cement ratio, water content and sand ratio are discussed through the mixture design tests. The formula for calculating the four key parameters of mixture proportions for SFRCAC are established through the statistical analysis of test results, which mainly consider the influences of recycled coarse aggregate (RCA) replacement ratio and steel fiber characteristic coefficient. The detailed procedure by using the new mixture proportion design method is illustrated with examples. The formulas established have the simple form, reflect the properties of RCA and steel fibers, enhance the mixture proportion design accuracy, and provide the reference for the mix proportion design of SFRCAC.

scholarly journals Usefulness of porphyry and amphibolites as a component of concrete for airfield pavements

2018 ◽  
Vol 163 ◽  
pp. 07002
Author(s):  
Małgorzata Linek ◽  
Piotr Nita ◽  
Paweł Wolka ◽  
Wojciech Żebrowski
Keyword(s):  
Bulk Density ◽  
Internal Structure ◽  
Coarse Aggregate ◽  
Cement Matrix ◽  
Physical Parameters ◽  
Hardened Concrete ◽  
Test Results ◽  
Laboratory Test Results ◽  
The Matrix

Coarse aggregate used as part of cement concrete is of primary significance for the obtained parameters of hardened concrete. In case of concretes intended for airfield pavements, the application of granite grit is recommended. Alternative to this type of aggregate in the form of porphyry and amphibolites aggregate was suggested. In order to assess the suitability of different aggregate types for concrete mixes, their bulk density, absorbability, polishing resistance, abrasion and crushing resistance were determined. Also, the internal structure of the suggested aggregates and its influence on changes of hardened concrete composite structure were subject to the assessment. The influence of aggregate type on the structure of cement matrix and contact areas between the matrix and aggregate grains were specified. The observed changes, in case of the internal structure of concretes based on porphyry and amphibolites aggregates, with reference to granite aggregate, resulted in changes of mechanical and physical parameters. Analyses included the determination of bulk density, absorbability, compression, bending and splitting resistance. According to the obtained laboratory test results, the significant influence of the aggregate type applied to the mix on parameters of hardened concrete, with regard to the application thereof to the airfield pavements was proved.

scholarly journals Effect of Plastic Synthetic Aggregate in the Production of Lightweight Concrete

2014 ◽  
Vol 2 (1) ◽  
pp. 83-88
Author(s):  
ELIVS M. MBADIKE ◽  
EZEOKPUBE G.C.
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Lightweight Concrete ◽  
Research Work ◽  
Control Test ◽  
Cement Ratio ◽  
Coarse Aggregates ◽  
Mix Proportion ◽  
Strength Tests ◽  
Average Compressive Strength

In this research work, the effect of plastic synthetic aggregate in the production of lightweight concrete was studied. The plastic synthetic aggregate was used to replace 0-40% of coarse aggregates. A mix proportion of 1:1.8:3.7 with water cement ratio of 0.47 were used. Concrete cubes of 150mmx150mmx150mm of coarse aggregate/plastic synthetic aggregate were cast and cured at 3,7,28,60 and 90 days respectively. At the end of each hydration period, the three concrete cubes for each hydration period were crushed and their average compressive strength recorded. A total of ninety (90) concrete cubes were cast. The result of the compressive strength tests for 5-40% replacement of coarse aggregates with plastic synthetic aggregate ranges from 8.07-36.71N/mm2 as against 24.58-41.21N/mm2 for the control test. The workability for 5-40% replacement of coarse aggregates with plastic synthetic aggregate ranges from 12-61mm as against 8mm for the control test (0% replacement).

scholarly journals EXPERIMENTAL INVESTIGATION ON LWC WITH COMPLETE REPLACEMENT OF COURSE AGGREGATE BY EPS BEADS

2020 ◽  
Vol 14 (1) ◽  
Author(s):  
Natalija Bede ◽  
Neira Torić Malić
Keyword(s):  
Experimental Investigation ◽  
Coarse Aggregate ◽  
Lightweight Concrete ◽  
Expanded Polystyrene ◽  
Hardened Concrete ◽  
Test Results ◽  
Mixture Proportioning ◽  
Complete Replacement ◽  
Total Replacement ◽  
Mix Proportion

In this paper, expanded polystyrene (EPS) lightweight concrete (LWC) was investigated. The mainaim was to design EPS LWC with the specified density of 1200 kg/m3 according to standard concretemix proportion. Mix proportion included total replacement of the conventional coarse aggregate bymaximum possible amount of EPS beads, which ensures concrete workability and prescribeddensity. The results demonstrated that exactly defined mixture-proportioning and casting procedureare required to achieve designed density. For designed EPS LWC mixture properties of freshlymixedconcrete and hardened concrete were analyzed. Based on test results it is concluded thatdesigned EPS LWC can be used for structural-insulating purpose such as floors and roofs.

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