Influence of Ground Calcium Carbonate Waste on the Properties of Green Self-Consolidating Concrete Prepared by Low-Quality Bagasse Ash and Rice Husk Ash.

Pusit Lertwattanaruk,Natt Makul

doi:10.3390/ma14154232

Abstract

Bagasse ash (BA) and rice husk ash (RHA) are by-products from electricity power plants. Ground calcium carbonate waste (GCW) is the by-product of the mining of calcium carbonate (CaCO3) in the color pigment manufacturing industry. Both BA and RHA are classified as low-quality pozzolanic materials, differing from GCW, which contains a high calcium oxide (CaO) content that leads to products equivalent to the hydration reaction. Therefore, GCW is likely able to improve the properties of self-consolidating concrete (SCC) incorporating BA and RHA. This paper discusses the production of green self-consolidating concrete (gSCC) and identifies the benefit of using GCW in gSCC prepared by triple combined GCW (10 and 20 wt%), BA (10, 20, and 30 wt%), and RHA (20 wt%). The results indicate that the majority of the gSCC retain acceptable flowability. The differences in the levels of gSCC substitution and the V-funnel flow results show general correlations with the increase in GCW. The gSCC prepared by 10 wt% GCW associated with 10 wt% BA and 20 wt% RHA was improved significantly. The filling and passing abilities of the gSCC were improved by using GCW. In addition, gSCC achieved mechanical property development and was able to minimize the consumption of OPC by up to 40%.

Highlights

The cement industry is becoming a severe threat to ecology due to its emission of carbon dioxide (CO2 )
It was noted that the w/b ratio for the green self-consolidating concrete (gSCC) mixtures incorporating bagasse ash (BA) varied in the range of 0.48 and 0.54; for the mixtures of gSCC with BA and rice husk ash (RHA), it varied from 0.49 and 0.56, and the w/b ratio requirements for the gSCCs with BA and RHA incorporating ground calcium carbonate waste (GCW) varied from 0.42 and 0.49
The distribution of smaller particle sizes improves the mixture viscosity, while the higher distribution of particle sizes improves with declining viscosity. This is because the improved ordinary Portland cement (OPC) + GCW or OPC contents decrease the amounts of water required

Summary

Introduction

The cement industry is becoming a severe threat to ecology due to its emission of carbon dioxide (CO2 ). Cement producers have tried to minimize the consumption of Portland cement through the application of supplementary cementitious materials, such as natural pozzolanic materials, to minimize emission of carbon dioxide (CO2 ) and partly substitute Portland cement in concretes. One of the conventional pozzolanic materials is fly ash obtained from thermal power plants where coal, such as anthracite, bituminous and lignite, is used as fuel to generate electricity. This byproduct can potentially provide additional positive effects for concrete such as increased workability [5,6], especially for utilization in self-consolidating concrete (SCC), and for the development of long-term compressive strength and other durability properties

Methods

Results

Conclusion