Early-Age Performance Analysis of Sludge Water Incorporation in High-Temperature Steam Cured Green High-Performance Concrete.

Beimeng Qi

doi:10.3390/ma15051912

Abstract

Sludge water (SW) with abundant sulfate ions (SO42−) was utilized in this work to replace freshwater (FW) to prepare green high performance concrete (GHPC). A comprehensive investigation was conducted to evaluate the early-age performance of GHPC specimen mixed with SW incorporation (GHPC-SW). High temperature steam curing (HTS) has been presented to prepare GHPC-SW specimens. The compressive strength of the GHPC-SW specimen cured by HTS curing for 2 days is 85.2 MPa, which is 34% higher than the compressive strength of the GHPC-SW specimen cured by 3 days standard curing as the reference. The mechanical property results reveal that the incorporation of SW makes no harmful effects on the strength formation of HPC specimens, compared with FW added specimens under the same curing methods. Moreover, XRD and TG analyses indicate that HTS curing can effectively improve the hydration degree of GHPC-SW specimens. MIP analysis has been conducted and the specimens cured by HTS curing exhibit a more refined pore structure with fewer harmful pores. This work lays a solid foundation for the utilization of SW in the concrete construction industry, which is resource saving and environmentally friendly.

Highlights

Green High-Performance Concrete.The concrete construction industry is meeting tremendous development in the last decades and is expected to be more prosperous in the future
85.2 MPa, which is 34% higher than the compressive strength of the green high performance concrete (GHPC)-Sludge water (SW) specimen cured by 3 days standard curing as the reference
The main purpose of this work is to clarify the specific effect of high-temperature steam curing on immobilizing the harmed ions inside the sludge water to improve the performance of the specimen, aiming at utilizing the sludge water as mixing water for cement-based materials with promising performance

Summary

Introduction

The concrete construction industry is meeting tremendous development in the last decades and is expected to be more prosperous in the future. The rapidly ongoing concrete construction industry has brought a great burden to the environment. In the process of actual concrete construction, the mass ratio of water to cement is around 0.5, which is very exaggerated for the utilization of rare freshwater resources [1]. In view of the increasing scarcity of freshwater resources in the world, there must be a reasonable way to rationally solve the huge amount of water needed by the growing concrete construction industry. A suitable substitution of freshwater for concrete construction is in great demand to solve this tough problem

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Conclusion