Special Issue: "Ceramics and Construction Materials".

The variety of material classes engaged for constructions is very wide, ranging from naturally occurring substances, such as stone materials and wood, to manufactured products such as inorganic binders, ceramic bricks, adhesives, metals, composites like concrete, bituminous or fibre-reinforced materials [...

Assessment of Alkali-Silica Reactivity of Aggregates by Concrete Expansion Tests in Alkaline Solutions at 38 °C.

A new accelerated concrete prism expansion test at 38 °C (accelerated CPT) is proposed for assessing the alkali-reactivity of concrete aggregates. In this test, concrete prisms with a standardized mix composition and different alkali contents are immersed in alkaline solutions with compositions simulating the pore liquid of hardened concretes. The concrete prism expansion test at 38 °C and RH > 95% (traditional CPT) was taken as a reference test, in order to define the appropriate expansion limit criterion for the proposed accelerated CPT.

Leaching test procedure for assessing the compliance of the chemical and environmental requirements of hardened woody biomass fly ash cement mixtures.

The compliance of the chemical and environmental requirements for using woody biomass fly ash (WBFA) as a mineral admixture in cement-based materials was studied in terms of the use of the cement-biomass fly ash concrete where the fluids surrounding and interacting with it renew themselves over time. The study was preceded by a preliminary characterization of WBFA whose results showed that the European chemical requirements (EN 450-1, 2012) established for the reuse of coal fly ash in cement-based materials (there is no normative for WBFA) were met except for the chloride content. A blend with a quite high content of WBFA (30%) and Portland cement (70%) was prepared to test the leaching behaviour of the cement-biomass fly ash concrete.

Alkali Release from Aggregates in Long-Service Concrete Structures: Laboratory Test Evaluation and ASR Prediction.

This paper proposes a simple model for predicting the development of deleterious expansion from alkali-silica reaction (ASR) in long-service concrete structures. This model is based on some composition and reactivity parameters related to ASR, including the long-term alkali contribution by aggregates to concrete structures. This alkali contribution was estimated by means of a laboratory extraction test, appositely developed in this study in order to maximize the alkali extraction within relatively short testing times and with low leaching solution/aggregate ratios.