Influence of Steel Slag-Superfine Blast Furnace Slag Composite Mineral Admixture on the Properties of Mortar and Concrete

Zhenguo Liu,Zongxian Huang,Prinya Chindaprasirt

doi:10.1155/2021/9983019

Abstract

A composite mineral admixture was prepared by steel slag and superfine blast furnace slag. The influence of superfine blast furnace slag content of the composite mixture on the mortar and concrete was investigated. The results show that the composite mineral admixture may decrease the strength of concrete at the early age but improve the strength development over time. Increasing the content of superfine blast furnace slag can reduce the degradation of the early strength. The reduction of the autogenous shrinkage and adiabatic temperature rise is significant when the composite mineral admixture is added. The reduction is more obvious when the water-to-solid ratio (w/s) is low. The results show that with steel slag and superfine blast furnace slag playing as complementary parts in the composite mineral admixture, it can be used as an effective substitute of cement.

Highlights

To combat halt global warming, the emission of CO2 and other greenhouse gases needs to be zero or even negative [1]
A composite mineral admixture was produced by adding the superfine blast furnace slag (SBFS) to Steel slag (SS). e workability and the compressive strength of the mortar were tested under different w/s. e compressive strength of the concrete mixed with composite mineral admixture was tested. e workability, compressive strength, and adiabatic temperature rise and autogenous shrinkage of the self-compacting concrete were tested in this paper
Fluidity is one of the important properties of concrete. e fluidity of concrete is affected by complex factors such as particle size distribution, surface humidity of the aggregate, and overall environment when mixing. erefore, in this paper, the fluidity ratio experiment of mortar is conducted to characterize the impact of the composite mineral admixture on the fluidity. e test was carried out according to the Chinese national standard GB/T 2419-2016. e w/s ratio of the mortar is fixed at 0.47 and the cementitious material-to-sand ratio is 1 : 3. e total content of the composite admixture was set as 30%. e fluidity of mortar is correlated to the packing density of mortar solid particles [32]

Summary

Introduction

To combat halt global warming, the emission of CO2 and other greenhouse gases needs to be zero or even negative [1]. Han et al [10] found that the pore structure of cement is refined when using fly ash-steel slag composite admixtures. Researches have shown that the addition of steel slag in concrete can reduce the reaction heat of cement hydration, the adiabatic temperature rises, and the early autogenous shrinkage of concrete [22]. Adding steel slag can reduce the compressive strength of concrete [23]. Blast furnace slag (BFS) is a mineral admixture with pozzolanic activity, which has been used as common supplementary cementitious materials in concrete [26]. Erefore, using SS and SBFS as complementary parts in the mineral admixture to replace parts of cement in concrete can be an effective way to reduce the amount of cement production. E compressive strength of the concrete mixed with composite mineral admixture was tested. A composite mineral admixture was produced by adding the SBFS to SS. e workability and the compressive strength of the mortar were tested under different w/s. e compressive strength of the concrete mixed with composite mineral admixture was tested. e workability, compressive strength, and adiabatic temperature rise and autogenous shrinkage of the self-compacting concrete were tested in this paper

Materials and Methods

Mortar Performance

Conclusions