Abstract
This experimental investigation explored the feasibility of using volcanic scoria rocks located in the northwestern region of Saudi Arabia for producing structural lightweight concretes (SLWCs). Several concrete mixes were designed, produced, and tested, to study the effects of various material and composition parameters on workability, unit weight, strength properties, and chloride penetration resistance of concrete. Test results indicated that the volcanic scoria could be used as coarse and fine aggregates for producing a series of lightweight concretes exhibiting strengths in the structural range. The SLWCs developed had a 7-day compressive strength of about 53-76 % of the 28-day compressive strength, a 28-day splitting tensile strength of about 911 % of the compressive strength, a 28-day flexural strength of about 10-15 % of compressive strength, and Poisson's ratio of about 0.19-0.21. The modulus of elasticity could be expressed with a formula similar to the one proposed by ACI 318-08. The stress-strain diagrams of the SLWCs produced were comparable to those for normal-weight concrete (NWC) with larger strain capacity at peak stress ranging from 2,600 to 3,300 mu compared to 2,000 mu for NWC. The 28-day chloride penetration resistance of the SLWCs developed falls within low to moderate range according to the criteria of ASTM C 1202.