Effect of fine recycled aggregates on the properties of non-cement blended materials

Wei-Ting Lin,Lukáš Fiala,Michaela Petříková,An Cheng,G.L Golewski

doi:10.1051/matecconf/202032301018

Wei-Ting Lin, Lukáš Fiala + Show 3 more

Open Access

https://doi.org/10.1051/matecconf/202032301018

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Abstract

In this study, the different proportions of co-fired fly ash and ground granulated blast-furnace slag were used to fully replace the cement as non-cement blended materials in a fixed water-cement ratio. The recycled fine aggregates were replaced with natural fine aggregates as 10%, 20%, 30%, 40% and 50%. The flowability, compressive strength, water absorption and scanning electron microscope observations were used as the engineered indices by adding different proportions of recycled fine aggregates. The test results indicated that the fluidity cannot be measured normally due to the increase in the proportion of recycled fine aggregates due to its higher absorbability. In the compressive strength test, the compressive strength decreased accordingly as the recycled fine aggregates increased due to the interface structure and the performance of recycled aggregates. The fine aggregates and other blended materials had poor cementation properties, resulting in a tendency for their compressive strength to decrease. However, the compressive strength can be controlled above 35 MPa of the green non-cement blended materials containing 20% recycled aggregates.

Highlights

Concrete is a mixture of cementitious materials, aggregate, and water
The flowability of non-cement blended materials containing various recycled fine aggregates is summarized in Tables 1 and 2
Due to the higher water absorbability of the recycled fine aggregates, different water demands had a significant effect on the flowability

Summary

Introduction

Concrete is a mixture of cementitious materials, aggregate, and water. Aggregate occupies over half of the concrete volume, which means that the quality of the aggregate largely determines many of the properties of the resulting concrete. Most of the fine and coarse aggregates in Taiwan are obtained via river dredging, sand and gravel mining, and importation. 90 million tons of fine and coarse aggregates are consumed in Taiwan every year. Continuing efforts to improve the infrastructure of the country mean that the demand for ready-mixed concrete is growing swiftly, further increasing the consumption of aggregate to levels that cannot be maintained indefinitely. Replacing some of the natural aggregates with recycled aggregates can have economic benefits and help to protect the environment

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