An Experimental Study on Alkali Silica Reaction of Concrete Specimen Using Steel Slag as Aggregate

So Yeong Choi,Eun Ik Yang

doi:10.3390/app10196699

Abstract

In this study, the characteristics of the alkali-silica reaction (ASR) expansion of steel slag itself, mortar bars, and concrete specimens using steel slag as aggregate are individually investigated by the expansion test method, to determine if steel slag aggregate in concrete can provide volume stability. The results show that when steel slag is aged in water for one month, its self-expansibility is below the permitted limit of 1.5% according to the JIS A 5015 standard. The ASR test results show that the ASR expansion of the mortar bars continuously increased with the increase in the test period. However, all mortar bars were below the permitted limit of 0.1% after 14 days according to the ASTM C 1260 standard. In contrast, the ASR expansion of concrete specimens was above the criteria prescribed by the ASTM C 1293 standard. From the results, the expansion of concrete specimens could not be controlled within the permitted limit by the ASTM 1293 criteria, even if the expansivity of steel slag did not exceed the criteria. Meanwhile, considering the crack propagation patterns of the concrete specimens, the cracks due to ASR expansion developed and connected even when the expansion was below the permitted limit. Besides, when mineral admixtures were used as the binder in the concrete specimens, there were discrepancies in the results between the expansion rate and the crack properties, such as maximum length and total crack length. Therefore, to accurately determine the change in volume due to ASR expansion in concrete using steel slag as coarse aggregate, it is necessary to check the crack patterns in addition to evaluating the expansion rate.

Highlights

Concrete is one of the most widely used construction materials
We evaluated the pattern of cracks caused by alkali-silica reaction (ASR) in the mineral admixtures, exhibiting a trend that is similar to be measured expansion rate
When steel slag used as fine aggregate in mortar bars, the ASR expansion increased with the increase in the duration of the test period

Summary

Introduction

Concrete is one of the most widely used construction materials. It has excellent properties, such as durability, versatility, and low cost, and, it is made up of basic ingredients such as a binder, aggregate, and water. The massive demand for concrete over the past few decades has led to the depletion of natural sources of aggregate. To address this shortage, the development of concrete using recycled aggregate has become a vital urban sustainability project. Example of typically in a recycled aggregate, steel slag is a waste product that is generated during the production of steel and makes up nearly 15–20% of the total amount of steel produced, by weight [1]. It is rapidly becoming an important construction material in sustainable development

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Conclusion