Development of rendering mortar from granite cutting waste and impact of accelerated aging environment on its adhesive strength

Abstract

The study evaluates the compatibility relationship of plaster bonds with the substrate under an accelerated aging environment for control and granite cutting waste (GCW) incorporated 1:3 cement sand mortar mixes. The investigation consists of material characterization, initial performance assessment and adhesion test under accelerated aging environment. The increased incorporation of GCW resulted in improved strength parameters of the cement mortar mix. For 30 % replacement, the compressive strength increased by 75 % compared to control mortar for 28 days curing period. Maximum flexural strength 2.99 N/mm2 is achieved for 30 %, and the highest adhesive strength, 0.89 N/mm2, is noted for 20 % replacement. Also, the microstructural studies are performed to assess the effect on the hydration of the cement. The 20 % optimal replacement of natural sand by GCW revealed 32.8 % better adhesiveness at 28 days age. The accelerated aging cycle testing was performed under standard controlled variations of temperature (freezing and thawing) and humidity as per BS EN 1015–12: 2000 and BS EN 1015–21: 2000. The study concluded that 20 % GCW substituted mortar faced 168 exposure cycles whereas control mortar faced 156 cycles before delamination, however, the values of the cycles are recorded as 112 and 124 respectively at critical peeling strength i.e., 0.3 MPa. The GCW incorporated mortar approximated at 8% higher adhesiveness due to its angularity of particles and surface roughness which is also advocated by its microstructural and mechanical performance assessment.