Alkali activated materials based on waste.

Abstract

The large volumes of Construction and Demolition Waste, Excavated Waste limestone, Quarry Waste generated in the construction industry, present significant challenges in disposal with environmental impacts. Recycling presents opportunities in reducing the disposal of waste material and also resulting in lower demands on the extraction of new resources. However low-quality inert waste which is generated in construction activities, presents limited opportunity in recycling, resulting in large volume of waste disposal. The increase in construction activity is leading to higher demands for construction products, with increased pressures on natural resource extraction including the extraction of aggregate and cement for the production of concrete and concrete products. In particular there is a large demand for concrete blocks in the construction industry. Cement as a binder in concrete, has a high embodied energy with negative impacts on the environment. The ReCON project (Large Volume Waste Recycling for Low-Impact High-Performance Concrete) refers to the recycling of large volumes of excavation waste consisting primarily of lower quality limestone and other materials, normally considered inadequate if used as aggregate in civil engineering applications, primarily due to low mechanical characteristics and impurities. The new product consists of a low-impact high-performance concrete, an eco-construction product based on waste excavation material. The innovation lies in the transformation of the waste into a high-performance construction product, without the use of cement as a binder. The new product is produced through a new technological process based on a production methodology consisting of key steps and resulting in premium quality products for the construction industry. The final product is strong, stable and durable for construction applications. The new product can effectively provide for the increasing demand for construction products. It can be presented in the form of building blocks, cladding panels or in other geometries and forms of high-performance construction products. The new product is based largely on waste, resulting in a reduction in consumption of raw materials and less waste disposed, and lower environmental impact. The new technology effectively transforms large quantities of waste into a resource, a low-impact high-performance material.