Material and Structural Performance Evaluations of Hwangtoh Admixtures and Recycled PET Fiber-Added Eco-Friendly Concrete for CO2 Emission Reduction

Materials

Bon-Min Koo²  Jang-Ho Jay Kim¹  Sung-Bae Kim² 

[1] Concrete Structural Engineering Laboratory, School of Civil and Environmental Engineering, Yonsei University, A274 Engineering Building #A, 134 Shinchon-dong, Seodaemun-gu, Seoul 120-794, Korea;Concrete Structural Engineering Laboratory, School of Civil and Environmental Engineering, Yonsei University, A404 Engineering Building #A, 134 Shinchon-dong, Seodaemun-gu, Seoul 120-794, Korea; E-Mail:

关键词: eco-friendly concrete;    Hwangtoh concrete;    admixtures;    short plastic fibers;    recycling PET plastic;    compressive strength;    crack control;    structural ductility;   

DOI  :  10.3390/ma7085959

来源: mdpi

【 摘 要 】

In order to reduce carbon dioxide (CO₂) emissions and produce an eco-friendly construction material, a type of concrete that uses a minimal amount of cement, yet still retains equivalent properties to ordinary cement concrete, has been developed and studied all over the world. Hwangtoh, a type of red clay broadly deposited around the world, has traditionally been considered an eco-friendly construction material, with bonus advantages of having health and cost benefits. Presently, Hwangtoh is not commonly used as a modern construction material due to properties such as low strength and high rates of shrinkage cracking. Recent studies, however, have shown that Hwangtoh can be used as a mineral admixture to improve the strength of concrete. In addition, polyethylene terephthalate (PET) fibers recycled from PET bottle waste can be used to control shrinkage cracks in Hwangtoh concrete. Therefore, in this study, performance verification is conducted on newly developed Hwangtoh concrete mixed with short recycled PET fibers. The results show that Hwangtoh concrete has compressive strength, elastic modulus, and pH properties that are similar to these features in ordinary cement concrete. The properties of carbonation depth and creep strain of Hwangtoh concrete, however, are larger and smaller, respectively, than in ordinary cement concrete. According to flexural tests, reinforced concrete (RC) specimens cast with Hwangtoh admixtures (with and without PET fibers) possess similar or better capacities than ordinary RC specimens. The addition of PET fibers significantly improves the structural ductility of RC specimens under normal environmental conditions. However, the implementations of the concrete in aggressive environment must be carefully considered, since a previous study result indicates degradation of its durability performance in aggressive environments, such as seawater [1]. The results of this study validate the possibility of using eco-friendly Hwangtoh concrete reinforced with recycled PET fibers as a structural material for modern construction.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.