Evaluation of the effect of micro-silica gel, polymer fibers, fly ash and RAP on the performance and durability of concrete pavers

Document Type : Research Paper

Authors

1 Department of Civil Engineering, Semnan Branch, Islamic Azad University, Semnan, Iran

2 Department of civil engineering, salmas branch, islamic azad university, salmas, iran

3 Graduated MSc. Department of Civil Engineering, Ahar Branch, Islamic Azad University, Ahar, Iran.

Abstract

In this article, one of the solutions to reduce greenhouse gases in block concrete pavements, i.e. the use of recycled materials investigated. concrete pavers blocks containing micro silica gel, fly ash, macro and micro polymer fibers, as well as reclaimed asphalt pavement (RAP) were made and in terms of compressive strength, bending resistance, durability against periods of freezing and thaw, skid resistance by the British pendulum method and wear resistance, by wide wheel abrasion method, were tested. The results showed that micro silica gel has the greatest effect in improving the compressive strength of the samples. The result of the flexural strength test was that micro silica gel increase the flexural strength by nearly 20%. Although polymeric fibers did not affect improving the compressive strength, they improved the modulus of rupture by about 5%. Meanwhile, two other materials, i.e. fly ash and RAP were not able significantly increase the flexural strength. The evaluation of the results of the durability test showed that the presence of three-tenths volume percent of macro polymeric twisted fibers preserves the compressive strength before and after 50 cycles of freezing and thawing. overall, the comparison of the ratio of the compressive strength of the samples after freezing and thawing to the strength of the samples before the test showed that the use of high percentages of micro silica gel, fly ash and macro polymer fibers is more than RAP and fibers and Micro polymers affect improving durability. The results of the abrasion and sliding resistance test also showed that different types of polymer fibers were more effective in improving the skid resistance of the samples. The test of abrasion resistance with wide wheel abrasion method also showed that micro silica gel plays a more effective role in keeping the surface of the sample blocks unified

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