Improving the Autogenous Self-Sealing of Mortar: Influence of Curing Condition

With the construction of projects under severe environments, new and higher requirements are put forward for the properties of concrete, especially the autogenous self-sealing property, which is greatly affected by the curing environment and the state of the water. Herein, six types of curing conditions, including in air with a relative humidity of 30%, 60%, and 95%; flowing water; wet-dry cycles; and static water, are designed to investigate the autogenous self-sealing of mortar under different curing conditions. The results showed that the self-sealing ratios are higher than 60% and the cracks are closed for the mortar undergoing the wet-dry cycles and the static water. However, the self-sealing ratios of mortar are lower than 10% and the cracks are almost unchanged when the mortar is cured in the air with a relative humidity (RH) of 30% and 60%. The static liquid water is more conducive to the continued hydration of cement and the formation of CaCO3 than the flowing water. The research provides guidance for the design of concrete and the improvement of autogenous self-sealing when the concrete serves in different environments.

Utilization of Recycled Liquid Crystal Display (LCD) Panel Waste in Concrete

The paper presents the possibility of using the liquid crystal display (LCD) waste as a partial substitute of fine aggregate. Concretes with two types of cement, CEM I 42.5 R and CEM II/B-S 42.5 N, with and without LCD addition, were investigated. The properties that influence the structures exposed to severe environments were examined. The results and analyses pertaining to their micro-structure, including interfacial transition zone (ITZ), were presented as well. All concretes exhibited good freeze–thaw (F–T) resistance after 150 F–T cycles. The water-tightness was established as 0.8 MPa. All concretes both with and without LCD achieved the same class C50/60.