The Durability of Mortar Containing Alkali Activated Fly Ash-Based Lightweight Aggregate.

Puput Risdanareni,Jianyun Wang,Nele De Belie,Philip Van Den Heede

doi:10.3390/ma14133741

Abstract

Beneficiating fly ash as valuable construction material such as artificial lightweight aggregate (LWA) could be an alternative solution to increase the utilization of the industrial by-product. However, generally, LWA is characterized by high porosity and a related high water absorption, which on the one hand allows production of lightweight mortar, but on the other hand can affect its performance. Thus, in this research, the durability performance of mortar composed with alkali-activated fly ash-based LWA, and commercial expanded clay (EC) LWA was investigated. The fly ash LWA was prepared in a pan granulator, with a 6-molar solution of NaOH mixed with Na2SiO3 in a Na2SiO3/NaOH weight ratio of 1.5 being used as activator (FA 6M LWA). The results revealed that mortar containing FA 6M LWA had equivalent mechanical strength with mortar containing EC LWA. The mortar containing FA 6M LWA had comparable capillary water uptake and chloride migration resistance with the reference and EC LWA mortar. Furthermore, the addition of FA 6M LWA was proven to enhance the carbonation resistance in the resulting mortar, due to the denser interfacial transition zone (ITZ) of mortar with LWA.

Highlights

IntroductionPublisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations
This paper presents the physical properties and durability aspects of mortar containing fly ash-based alkali activated lightweight aggregate
The results show that the properties of hardened mortar containing FA 6M lightweight aggregate (LWA) are acceptable compared to a reference without

Summary

Introduction

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. In the past decade, recycling industrial by-products or waste into more valuable materials has become the concern of many researchers around the world. It is reported that in 2015, the global production of coal combustion products (CCP) such fly ash and bottom ash was 780 metric tons, and was expected to increase by 1.6% annually [1].

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Conclusion