Relationships between microstructure and transport properties in mortar containing recycled ceramic powder

Abstract

Sustainable utilization of ceramic wastes in construction has gained increasing interest, but the microstructure and transport properties of ceramic-modified construction materials remain to be explored before in-situ engineering application. This paper presents an experimental study on microstructure, mechanical properties and transport properties of cement mortars containing different percentages of ceramic powders (CPs) up to 40%. Microstructure of CP-cement mortars was measured using mercury intrusion porosimetry, water vapor sorption isotherm and scanning electron microscopy techniques. Mechanical properties including compressive strength and flexural strength as well as transport properties including gas permeability and capillary sorptivity were measured. Results indicate that ceramic powder can greatly refine the pore structure of CP-cement mortars. Because of the homogenization and densification effects of ceramic powder on mortar matrices and interfacial transition zones, the compressive and flexural strengths of CP-cement mortars at 180 d are around 80 MPa and 10 MPa, respectively. Both gas permeability and capillary sorptivity decrease substantially as ceramic powder content increases and exhibit linear correlations with pore structure characteristics such as total porosity and critical pore size. Ceramic powder can lower the manufacture costs of concrete and obtain better durability. Therefore, ceramic powder can be considered as a promising supplementary material to develop sustainable and durable cement-based materials for future engineering applications.

Assessment of the Permeability to Aggressive Agents of Concrete with Recycled Cement and Mixed Recycled Aggregate

“…Further to the plots in Figure 3b, the O 2 permeability coefficient and open porosity were linearly and closely (R 2 > 0.91) correlated in the mixes studied and the former was observed to increase proportionally to the latter. Similar findings were reported for mixes prepared with other additions (fly ash [40], rice husk ash [41] and masonry dust [42]) to replace cement; mixes containing RCA fines and coarse aggregates [43]; and mixes made with masonry aggregate [36]. The inference drawn from such a close correlation indicates that this property may serve as an index for assessing the material's porosity and, consequently, its durability.…”

Behaviour of recycled tyre polymer fibre reinforced concrete under dynamic splitting tension

“…20. The unit costs of constituent materials except RTP fibres are based on the commercial market prices [37,48]. The unit cost of RTP fibres was provided by the supplier, which is around 0.5 USD/kg.…”

Durability of eco-efficient binary cement mortars based on ichu ash: Effect on carbonation and chloride resistance

“…Such behaviour is associated with the refinement of the pore network and its lower connectivity (see section 3.2.3). It should be noted that this decrease in gas permeability is substantially higher than for other materials such as ceramic waste (for which a 5% decline is obtained with respect to conventional cement at a 10% substitution level) [46] or slags (21% decrease compared to conventional cement, at a 30% substitution level) [47]. This enhanced decrease in gas permeability is closely related to the intrinsic properties of this new SCM [36], which presents a higher lime-fixing capacity (pozzolanic activity) at short ages than ceramic-based pozzolans and slags.…”