Evaluation of Mechanical Characteristics of Cement Mortar with Fine Recycled Concrete Aggregates (FRCA)

Abstract

One of the growing demands in concrete manufacture is the availability of natural fine aggregates, which account for 35% to 45% of the total concrete. An alternative method of disposal of fine recycled concrete aggregates (FRCA) generated from demolition and construction waste (C&DW) is their usage in mortar and the development of recycled mortar. The main aim of this research work is to evaluate the viability of incorporating FRCA from urban C&DW for the manufacture of cement-based mortars. Simple processing techniques like washing and sieving are adopted to improve the FRCA quality. Physical and chemical characterization of ingredients is carried out. In total four mixes of 1:3 (cement: sand) mortar with partial replacement of normalized sand with FRCA (0%, 25%, 50%, and 100%) are evaluated for mechanical properties. Water to cement ratio for all four mortar mixes are determined by fixed consistency. Mechanical and physical properties like density, compressive strength, and flexural strength are studied for various curing periods, and the result is that the optimum usage of FRCA is 25% based on a 90-day curing period.

The Performance of Concrete Made with Secondary Products—Recycled Coarse Aggregates, Recycled Cement Mortar, and Fly Ash–Slag Mix

“…According to Eurostat data, the total amount of waste generated in Europe by households and companies by economic activity, according to the statistical nomenclature of economic activities of the European Community, is approximately 2535 billion tons per year, of which 36% (923 billion tons) is industrial waste from the construction industry [5]. More than one-third of all waste generated in the EU comes from the construction industry, of which up to 90% reaching landfills could be recycled and/or reused [6,7], and around 40-67% of construction and demolition waste is concrete [8].…”

“…For the above-mentioned reasons, researchers are making efforts to study recycling opportunities in concrete and cement production. After all, recycling has three benefits: it reduces the demand for new resources, it cuts down on production energy costs, and it recycles waste that would otherwise be landfilled [7]. For instance, over the years, alternative binders such as blast furnace slag [49], fly ash [50], or silica fume [51], which are industrial by-products, have become valuable materials for concrete production.…”

Freezing and Thawing Resistance of Fine Recycled Concrete Aggregate (FRCA) Mixtures Designed with Distinct Techniques

“…Direct replacement methods (DRM), either partial/full or by weight/volume, are one of the earliest attempts to mixture proportion concrete using FRCA. Studies show that a replacement ratio of less than 30% provides optimal results [29,[31][32][33]38,[42][43][44], although suitable properties were achieved using 100% replacement in some cases. Moreover, results of recycled concrete mixtures designed through DRM were verified to be extremely variable.…”

Effect of Waste Basalt Fines and Recycled Concrete Components on Mechanical, Water Absorption, and Microstructure Characteristics of Concrete

“…In 2017, about 45 billion tons of natural aggregates were extracted, while in 2025, the estimated extracted amount is predicted to rise to 66 billion tons. Moreover, the cement industries consume aggregates at a rate of about 40 billion tons/year worldwide [1][2][3]. To reduce the consumed amount of natural aggregates, research into the reuse of construction waste materials and the management of their disposal can decrease their removal costs and environmental impact (EI) [4].…”