Assessment of the application of CEM III with exposed aggregate as an alternative to CEM I for road pavements

Abstract

The article presents a results of study on the impact of replacing CEM I SR3/NA by CEMIII/A LH/HSR/NAon the mechanical properties and durability of pavement concrete with exposed aggregate. Was used granite aggregate and washed sand. Water/cement (w / c) ratio in the tested concretes constituted 0.35 and 0.4 and part of the cement was replaced with a 5% addition of natural pozzolana – zeolite. Compressive strength tests were performed after 3, 7, 28 and 56 days, tests of tensile strength test by splitting method and flexural strength two-point loading tests. The characteristics of the air pores and the rate of water absorption by concrete surface of the samples cut out from the slabs with exposed aggregate were presented. The resistance of the surface to exfoliation after 56 cycles of freezing-thawing in NaCl solution was tested. Based on the results obtained, it was found that when designing the composition of the concrete intended for the upper layer of the pavement, it is necessary to ensure high tensile strength, appropriate in the XF4 environment and with the decrease in the w / c < 0.4, a reduction in capillary porosity of the cement paste is obtained, and the same the durability of concrete is increased due to the improved strength parameters in the contact zone between coarse aggregate grains and cement paste. The research also showed a significant influence of proper cure on the mechanical properties and durability of pavement concrete.

Keywords

• road pavement
• concrete
• exposed aggregate
• compressive strength
• tensile strength
• cement