Investigation of the effect of petrological contents on the engineering properties of carbonates aggregates

Abstract

Rock aggregates have widespread applications in construction projects, and their engineering properties play a key role in their application. Aggregate's engineering properties are affected by their inherited petrographic characteristics. In this paper, the impact of various petrographic characteristics on the engineering properties of crushed limestone is evaluated. Petrographic analyses and common quality control aggregate tests were performed on 25 carbonate rock samples. The engineering tests conducted include Los Angeles abrasion value (LAAV), aggregate crushing value (ACV), slake durability index (SDI), magnesium sulfate soundness (SS), and water absorption (WA). Also, the petrographic analyses performed on thin sections involved calculating the percentage of fossil grains (FG), non-fossil grains (NFG), meso-scale porosity and voids (LP), micro-scale porosity and voids (SP), micrite (M), sparite (S), dolomitic grains and cement (D), quartz and chert (Q), clay (C), and opaque minerals (O). Statistical analyses were applied to the dataset to evaluate the correlation and obtain the possible relationships between aggregates engineering and petrographic properties. The results indicated that C, LP, O, and SP have an important effect on the engineering properties of carbonate aggregates. Multiple regression analyses were conducted and R2 values higher than 0.84 were obtained, except for the SS. These equations were evaluated by using various data obtained from scientific resources, and their error values were calculated. The error analysis proved the accuracy of the obtained equations. To investigate the quality of each sample according to allowable limit values, based on international standards, real and estimated values were used. Results proved that selecting the most important petrographical parameters for predicting aggregates engineering properties is quite simple and efficient and can be used in the preliminary stages of aggregate evaluations.