Utilisation of waste marble powder as low-cost cementing materials in the production of mortar

Abstract

Marble industries produce vast amounts of wastes, and this is detrimental to the environment. Accordingly, these waste materials require appropriate management to ensure a cleaner environment. Given that, the utilisation of recycled materials in construction is desirable, owing to the space saved from landfill purposes and reduction in carbon dioxide (CO2) as well as the lower cost related to the waste materials. Subsequently, this paper investigated the effects of adding waste marble powder (WMP) as filler on the strength performance of mortar, with different Blaine Specific Surface (BSS) on the precise class of resistance of the Artificial Cement Portland CEM I 42.5. The experimental investigation and statistical analysis were carried out on mortar mixes containing four different types of marble powder as the filler (F1, F2, F3, F4) with BSS values of 3860, 5640, 7620 and 9280 cm2/g, respectively. Substitution rates of 5, 15, and 25% were applied. In addition, the water/cement + filler ratios (W/(C + F)) or W/Ceq and the true class of resistance of the new cement were measured for each mix. Moreover, the theoretical models (termed as equivalence models), which enabled the determination of the precise class of resistance of the cement and W/Ceq ratios as a function of the BSS of the used marble fillers and substitution rate, were developed. The obtained results revealed that 5% substitution of cement by the marble powder provided compressive strength values similar to that of the control mix for all types of filler. However, with further increase in the substitution rate, the compressive strength reduced. Subsequently, both the experimental and theoretical results presented a good agreement. It was concluded that the proper use of waste marble powder as a partial replacement of cement would have environmental benefits, and simultaneously, increase the feasibility of marble stone industries.