Effect of Internal Pores Formed by a Superabsorbent Polymer on Durability and Drying Shrinkage of Concrete Specimens.

Il-Sun Kim,So-Yeong Choi,Eun-Ik Yang,Yoon-Suk Choi

doi:10.3390/ma14185199

Il-Sun Kim, So-Yeong Choi + Show 2 more

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https://doi.org/10.3390/ma14185199

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Abstract

In this study, the effect of internal pores formed by a superabsorbent polymer (SAP) was analyzed by evaluating the compressive strength, chloride penetration depth, drying shrinkage, and pore size distribution of SAP-containing concrete, while securing workability using a water-reducing agent (WRA). The experimental results showed that the amount of WRA necessary increased as the amount of SAP added increased, and that the compressive strength was the highest when the SAP content was 1.5% of the concrete mix. Drying shrinkage tended to decrease as the SAP content increased, and it decreased by approximately 31–41% when the SAP content was 2.0% compared to that of the reference mix. The SAP expanded by approximately three times inside concrete, and it was distributed within the internal pores of air-entrained concrete. The optimal SAP content in concrete mix was 1.5%, and an SAP content of 2.0% or higher adversely affected the workability and compressive strength.

Highlights

Marijana Hadzima-NyarkoConcrete is undoubtedly an excellent civil and building material
The water-reducing agent (WRA) ratio showed a tendency to linearly increase until the superabsorbent polymer (SAP) ratio reached reached 1.5%
As the SAP ratio increased by 0.1%, the WRA ratio had to be increased by 0.04%

Summary

Introduction

Marijana Hadzima-NyarkoConcrete is undoubtedly an excellent civil and building material. SAPs expand inside fresh concrete by absorbing mixing water and they contract in a dry environment by releasing moisture. In this case, the released water supplies moisture to the concrete, creating an internal curing effect. As a result of the internal curing effect, the durability of concrete improves owing to reduced shrinkage and a greater strength [9,11]. Since internal curing by SAPs can significantly reduce autogenous shrinkage and improve concrete strength, many studies have been conducted on this subject [12,13,14,15,16,17,18]

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