Effect of New Composite Cement Containing Volcanic Ash and Limestone on Mechanical Properties and Salt Scaling Resistance of Concrete

Abstract

Salt scaling is one of the major damage problems for cementitious materials in cold environments. One of the main objectives of this work is to determine effects of air void and a new composite portland cement containing volcanic ash (tuff) and limestone on deicer scaling resistance of concrete. Another objective is to investigate the effects of compressive strength, tensile strength, abrasion resistance, and water penetration on the freeze-thaw deicer salt scaling. The specimens were tested for salt scaling resistance in accordance with standard test methods. The scanner method is used to quantify air void characteristics. In the scanner method, the polished surface is scanned twice on a high-resolution flatbed scanner. The polished surface of concrete sample is scanned in two different conditions; its natural and contrast-enhanced condition. Then the captured images are analyzed by a Visual Basic script. Tensile and surface strengths of concrete play an important role on salt scaling resistance. There is no appropriate relationship between compressive strength and salt scaling resistance, when concrete mixtures are made with various cementitious materials. Results reveal that the mixture containing composite cement with entrained air has the best performance in salt scaling.