A STUDY FOR IMPACT OF MORSEL ADDITIVES AND INITIAL CURINGS ON BLAST-FURNACE SLAG BLENDED CEMENT CONCRETE

Abstract

 Medium volume blast furnace slag concrete has been highly expected to contribute to reducing carbon dioxide emission in concrete production. However, it was found that this concrete appears to be prone to shrinkage cracking specifically under hot summer climate. To improve this negative performance, this study focused to utilize morsel additives and water curing. The morsel additives are gypsum and calcium carbonate, with which binder is called low shrinkage BFS. Furthermore, to reduce prominent autogenous shrinkage, initial water curing is to be investigated. As a result, combining low shrinkage BFS and water curing was found to significantly strengthen shrinkage cracking resistance, which was expressed by cracking age resulted in restrained shrinkage cracking tests. Furthermore, curing experiment showed that water curing may be substituted by water covered curing on element surface in construction site as a simple and economical measure to supply water to concrete at initial stage of hardening.