Valorization of waste from sand wash muds of an aggregates plant: Evaluation as a supplementary cementitious material

Abstract

The reuse and reincorporation of waste generated in the production processes are becoming increasingly important in the world, due to the double effect that it has in terms of sustainability. The first one is the environmental factor, since the impact generated is reduced by reducing the amount of wastes. The second one is the financial factor, since new products are developed that companies did not initially have, generating financial profitability. Therefore, this research evaluates the possible reuse of waste from gravel and sand wash mud of an aggregate plant as a supplementary cementitious material (SCM) after being thermally activated, seeking to promote the circular economy in the construction materials sector. The physical, chemical, and mineralogical characterization of the waste is presented and its pozzolanic activity was evaluated by means of the SAI-strength activity index. It was found that despite its low content of clay minerals, the thermally activated waste had very good performance as SCM with SAI between 81 and 106 with a tendency to increase with the age of cure. Showing that this can be a very promising potential use for this kind of waste.

Comparative effects of different real conditions in the microstructure and properties of ternary blended cement mortars for being used in rehabilitation works

“…On the other hand, the search of solutions for reducing the energy and environmental problems caused by the manufacture of Portland cement (Benhelal et al, 2021) is a main issue to be addressed in the construction materials field, within the current context with the aim of lessening the global warming, according to the objectives of sustainable development. In this line, the development of eco-friendly cements (Restrepo-Baena et al, 2020;Andrade and Sanjuán, 2021) with additions, could be a good alternative for contributing to reach a more sustainable industry of cement. Among the different environmental advantages for the utilization of blended cements with additions, it is noteworthy to underline the lessening of CO 2 emissions and energy consumption, because of the lower quantity of clinker required for manufacturing commercial cements.…”

Study of excavated clays with kaolinite and dickite as pozzolanic materials

“…In the case of the Bogotá city (Colombia), the soil is formed by lacustrine deposits and its mineralogical composition includes as much as 50 % quartz, 15 -42 % feldspars and 15 -30 % clay [6]. Some mining by-products made up of clays have been valued by being used as supplementary cementitious materials, contributing to their environmental management [7,8], since it is possible to remove structural water by thermal treatments obtaining an amorphous phase with pozzolanic activity as has traditionally been done with kaolinitic clays [9][10][11] and how is being done with multicomponent clays [12][13][14].…”