Surface Heat Reduction of Asphalt Concrete by Top Filling with Mortar Prepared by Oyster Shell Aggregate and Ground Granulated Blast Furnace Slag and Their Strength in Different Curing Condition

Abstract

The study was an attempt to elucidate the compressive strength of oyster shell (OS) aggregate and ground granulated blast furnace slag mortar in different curing condition and to know their amount of solar reflectance, brightness and heat absorption characteristic of the pavements surface which was prepared with study mortar by top filling on open graded asphalt concrete. The compressive strength cylindrical samples were cured in 10℃, 20℃ and 30℃. Light irradiation test conducted in natural condition in 3 consecutive days also in environmentally controlled room, 3 hours light irradiation was applied on 7 types of sample pavements surface. The amount of solar reflection was measured by spectrometric analysis with the wavelength of 380-2,600 nm. At 28 days age, 30℃ water curing samples showed the highest strength for river sand mortar samples, and 20℃ water curing showed the highest compressive strength for OS mortar samples except high early strength Portland cement (HSPC)-OS mortar. Highest compressive strength of HSPC-OS mortar was for 20℃ air curing sample. In brightness, light irradiation test and spectrometric analysis showed that ordinary Portland cement (OPC)-Slag-OS sample is the brightest and highest solar reflector as well as it showed lowest surface temperature within the study pavements.