This paper presents the residual mechanical properties of concrete made with crushed bricks and clay roof tile aggregates after exposure to high temperatures. One referent mixture and eight mixtures with different percentages of replacement of natural aggregate by crushed bricks and roof tiles are experimentally tested. The properties of the concrete were measured before and after exposure to 2...

Calcium carbonate and calcium-magnesium carbonate in the form of limestone, dolomite, marl, chalk, and Oyster shell are one of the most widely utilized non-metallic materials in the industrial world. The largest use of limestone or calcium carbonate is in the cement industry where it is used as a source of CaO and also in the concrete industry where it is used as the primary coarse aggregate. F...

We analyze a signature scheme described in a recent Internet Draft, and highlight a variant (based on prior work of Micali and Leighton) that offers improved concrete security.

Recycled demolished concrete (DC) as recycled aggregate (RA) and recycled aggregate concrete (RAC) is generally suitable for most construction applications. Low-grade applications, including sub-base and roadwork, have been implemented in many countries; however, higher-grade activities are rarely considered. This paper examines relationships among DC characteristics, properties of their RA and...

The huge quantity of concrete is consumed by the construction industry all over the world, probably second largest after water. In India, the conventional concrete is produced by using natural sand from riverbeds as fine aggregate. Dwindling sand resources poses the environmental problem and hence government restrictions on sand quarrying resulted in scarcity and significant increase in its cos...

A social study was performed on how to assess concrete material sustainability in the Japanese concrete industry. The perspectives were converted to weights using Analytic Hierarchy Process, a multi-criteria decision-making tool, and the sustainability of several concrete mixtures was compared. It was found that fly ash concrete mixes with normal or recycled aggregates had the highest weights, ...

High-calcium fly ash (FH) is the combustion residue from electric power plants burning lignite or sub-bituminous coal. As a mineral admixture, FH can be used to produce high-strength concrete and high-performance concrete. The development of chemical and mechanical properties is a crucial factor for appropriately using FH in the concrete industry. To achieve sustainable development in the concr...

A unique, multi-phase, random, complex, and composite material, concrete provides both strength and impermeability to engineered structures. Unlike most construction materials, the properties of concrete continue to develop over time and in place—assisting processing and fabrication. Testing and quality assurance, however, become more complicated. For instance, having to wait 28 days to ensure ...