Engineering Properties and Microstructural Performance of Low Energy Super-Sulfated Cement Using Industrial Waste Anhydrite

Tsung-Yuan Huang,Hoang-Anh Nguyen,Ta-Peng Chang,Chun-Tao Chen,Yu-Wen Liu,Katsuyuki Kida

doi:10.1051/matecconf/201713004001

Abstract

This study aims at proposing the mix proportions of low energy super-sulfated cement (SSC) concrete from industrial waste anhydrite from circulating fluidized bed combustion (CFBC) fly ash (CFA) as an alternative sulfate activator of ground granulated blast furnace slag (GGBFS/slag). The optimized mix proportion of the SSC was carried out by using mixture of different amounts of CFA in range of 25—45 wt.% and various quantities of ordinary Portland cement (OPC) in range of 0 — 10 wt.% to trigger the hydration of slag. Experimental results showed that with the expected slump at values of 190 — 220 mm, the 28-day compressive strengths of the concrete with low energy SSC reached 43.69 MPa which can be feasibly applied for widely advanced construction materials. The OPC in range of 3 — 5 wt.% and 25 wt.% of CFA were considered as the optimum ingredients of the activator and was suggested to be used for fabricating the low energy SSC concrete with the good performance on compressive strength, dynamic Young’s modulus, UPV measurement, and stabilized change of length. The OPC additive up to 10 wt.% was encouraged to be used for producing the SSC concrete with significant reduction on creep.

Highlights

2.1 Materials and mix proportions low energy super-sulfated cement (SSC)The commercial Type I Portland cement in accordance to ASTM C150 and circulating fluidized bed combustion (CFBC) fly ash (CFA) were used as the alkali and sulfate activators, respectively
The effects of both CFBC fly ash (CFA) and ordinary Portland cement (OPC) as partial replacements of slag on the workability of the fresh low energy SSC concretes were insensitive because Table 2 shows that the expected slump values of the fresh SSC concretes were approached by using the equivalent amount of SP value
The increases of either OPC or CFA replacing for slag led to the decrease in both the initial and final setting time of the resulting low energy SSC concretes, which obviously implies that the hydration rate of the SSC binder was accelerated with the increase of the activators

Summary

Introduction

The commercial Type I Portland cement in accordance to ASTM C150 and CFBC fly ash (CFA) were used as the alkali and sulfate activators, respectively. Ground granulated blast furnace slag (GGBFS) and CFBC fly ash MATEC Web of Conferences (CFA) were used as the primary powder. Crushed natural stone with maximum size of 20 mm and river sand with fineness modulus (FM) of 2.9 were used as coarse and fine aggregates, respectively. The specific gravities of sand and crushed stone are 2.65 and 2.67, and water absorptions are 0.8% and 1.0%, respectively. Both sand and crushed stone were carefully washed to ensure good binding in concrete mixtures

Objectives

Results

Conclusion