Lightweight concrete incorporating volcanic materials

This paper describes properties of lightweight concrete obtained by incorporating volcanic-materials-based blended cements and pumice aggregates. Blended cements are produced by replacing ASTM Type I Portland cement with 20% volcanic ash and finely ground pumice. Properties of fresh lightweight concrete mixtures (such as slump and air content) along with their mechanical properties (such as density, compressive/tensile strength and modulus of elasticity) are described. The durability and microstructural characteristics are investigated by drying shrinkage, water permeability, mercury intrusion porosimetry, differential scanning calorimetry and microhardness tests. The investigation suggests that volcanic-materials-based blended cements in combination with pumice aggregates can be used for the production of lightweight concrete for structural applications, having satisfactory strength and durability characteristics. The use of volcanic ash/pumice-based blended cements induces the beneficial effect of reducing drying shrinkage and water permeability as well as refinement of pore structures and better interfacial transition zone. Development and use of such inexpensive and environmentally friendly lightweight concretes can be extremely helpful for the sustainable development and rehabilitation of volcanic disaster areas around the world.