Rationalizing the impact of aging on fiber–matrix interface and stability of cement-based composites submitted to carbonation at early ages

Abstract

The objective of this work is to show the effect of carbonation at early stages on fiber-cement composites and impact on hydration, chemical and dimension stability. Carbonation increased the content of CaCO 3 polymorphs and consumed Ca(OH) 2 and other hydrated calcium phases. Micrographs and energydispersive spectrometry showed the CaCO 3 formed is precipitated in the pore structure of the matrix, decreasing diffusion of Si, S, and Al during hydration. Therefore, a refining process of pore sizes is produced, and fiber-matrix interface in carbonated composites was improved, leading to volume stabilization of the composite, as indicated by lower drying shrinkage and lower porosity.

High strength oil palm shell concrete beams reinforced with steel fibres

“…Meanwhile past studies on fibre-reinforced concrete reported significant enhancement of the mechanical properties, cracking resistance and durability compared to the conventional concrete (3,7,8,(13)(14)(15)(16)(17)(18)(19). The other reported advantages of steel fibres in concrete include improving toughness (19), ductility (20), flexural behaviours (21) and impact and blast resistance (5).…”

Carbonation-Induced Mineralogical Changes in Coal Mining Waste Blended Cement Pastes and Their Influence on Mechanical and Microporosity Properties

“…Carbon dioxide dissolves in water to form H 2 CO 3 , which reacts with the Ca 2+ sourced primarily from portlandite dissolution and C-S-H gel decalcification [15,16]. To date most studies on cementitious material carbonation have focused on the effect of permeability, the hydration chemistry of carbonated structural concrete and changes in porosity [17], or on the use of cellulose fibres as reinforcement in composite manufacture to enhance durability [18]. General studies on the effect of CO 2 on cements have shown that OPCs exhibit higher carbonation resistance than pozzolan-bearing blended cements [19].…”

Avaliação da influência de diferentes métodos de cura na permeabilidade e no desempenho físico-mecânico de telhas de fibrocimento reforçadas com fibras poliméricas

“…As discussões embasadas no conhecimento adquirido pela revisão bibliográfica somadas aos resultados obtidos métodos utilizados fundamentam as conclusões obtidas no estudo. (POPESCU et al, 2014;TONOLI et al, 2016). Os carbonatos mais cristalizados se decompõem em temperaturas entre 750 a 950°C (KIM et al, 2013;TONOLI et al, 2019 -GONZÁLEZ et al, 2006;KIM et al, 2013;TONOLI et al, 2016).…”

“…(POPESCU et al, 2014;TONOLI et al, 2016). Os carbonatos mais cristalizados se decompõem em temperaturas entre 750 a 950°C (KIM et al, 2013;TONOLI et al, 2019 -GONZÁLEZ et al, 2006;KIM et al, 2013;TONOLI et al, 2016). As reações entre Ca(OH)2 e H2CO3 formam diferentes fases de CaCO3, como carbonato de cálcio amorfo, vaterita, aragonita e calcita.…”

“…É também abordada a avaliação da CA como um método de cura em idades iniciais para conferir melhor desempenho nas propriedades físicomecânicas reduzir a retração por secagem e mitigar a permeabilidade das telhas de fibrocimento. (TONOLI et al, 2016).…”