Abstract:

The fine structure of grass-planted concrete plays a crucial role in determining its compressive strength. Understanding its physicochemical properties is essential for enhancing the performance of porous grass-planted concrete. We investigated the pore structure using Rapid Air 457 device, examined the SEM, XRD diffraction, and mechanical properties of grass-planted concrete. Results revealed that increasing the dosage of silica fume powder and fly ash reduced the finescale pore content to 0.85% and 0.22%, respectively. The average pore size decreased to less than 80 μm, and the spacing coefficient was significantly altered, which enhanced the 28-day maximum compressive strength of the grass-planted concrete up to 10.1 MPa and 11.3 MPa, respectively. SEM and XRD diffraction tests together with Dessication Susceptibility (DES) analysis unveiled that the mass ratio of Ca to Si in grass-planted concrete declined, indicating that the hydration products of silica fume powder and fly ash densified the internal structure of the cementitious material of grass-planted concrete, positively affecting its compressive strength. This research fills a gap in the study of the fine pore structure of grass-planted concrete.

Key words: grass-planted concrete, mesoscopic structure, compressive strength, silica fume, fly ash