Water-retentive asphalt concrete (WRAC), produced by incorporating water-retentive slurry (WRS) into
porous asphalt concrete (PAC), could significantly reduce the surface temperature of pavements and is
currently considered a promising tool for alleviating urban heat island effect. Based on laboratory test
and microstructural analysis, the present study investigated the effects of varying the proportions of
ground granulated blast furnace fly ash, calcium hydroxide and mixing water amount on workability
of fresh WRS. In addition, the water absorbing capacity, compressive strength and flexural strength of
the cured (hardened) WRS were determined. The microstructures of hardened WRS were examined using
scanning electron microscopy in order to better understand the effect of hydration level and pore structure
on the water absorbing capacity and mechanical properties of hardened WRS. The results showed
that materials composition have significant effects on the water absorbing capacity, compressive strength
and flexural strength of hardened water-retentive slurry, as well as the workability of fresh WRS. WRAC
showed good moisture resistance, rutting resistance and low deformation resistance comparable to the
control PAC. However, the use of WRAC resulted in a temperature drop of about 10 C compared to
the control PAC.