Water transport in binary eco-cements containing coal mining waste

This study explores certain indirect, water transport-related durability indicators for mortars made with cement in which 20% or 50% of the ordinary portland cement (OPC) is replaced by thermally activated coal mining waste (ACMW). The valorisation of ACMW is triply beneficial, environmentally speak...

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Detalhes bibliográficos
Autores: Caneda-Martínez, Laura, Medina, César, Sánchez de Rojas, María Isabel, Frías, Moisés
Formato: artículo
Estado:Versión enviada para evaluación y publicación
Fecha de publicación:2019
País:España
Recursos:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/196639
Acesso em linha:http://hdl.handle.net/10261/196639
Access Level:acceso abierto
Palavra-chave:Activated coal mining waste
Supplementary cementitious materials
Descrição
Resumo:This study explores certain indirect, water transport-related durability indicators for mortars made with cement in which 20% or 50% of the ordinary portland cement (OPC) is replaced by thermally activated coal mining waste (ACMW). The valorisation of ACMW is triply beneficial, environmentally speaking, for it reduces waste stockpiling and its processing emits less CO2 and requires less fossil fuel-based energy than OPC manufacture. Its addition was observed to generate a finer pore structure and a larger volume of pores accessible to water. In mortars with 50% ACMW, pore volume rose by approximately 30%, lowering density and consequently mechanical strength. Total water absorption declined by 13% and capillary absorption by 24% in mortars with 20% ACMW, whilst no significant variations in either parameter relative to the OPC reference were found in the materials with 50% replacement ratios. Permeability to water penetration under pressure rose substantially in both blended mortars, although as the maximum and mean depth values lay within the limits specified in Spain's structural concrete code, the materials would be classified as impermeable. The mortars with 20% replacement exhibited no greater drying shrinkage than the OPC materials, whereas the mortars bearing 50% ACMW shrank by approximately 50% more than the reference.