Mechanical and durability properties of self-compacting heavy mortars produced using ground barite aggregate

In this study, barite aggregates were utilised in three distinct gradations (0-4 mm, 0-2 mm, and 45-75 µm). In addition to the aggregate, self-compacting heavy mortar (SCHM) was produced using Portland cement (PC) as binder, fly ash (FA) as pozzolanic material and superplasticizer (SA) as chemical. To this end, a series of mixtures were produced, incorporating barite aggregates and fly ash in varying proportions. In all these mixtures, the amount of PC was reduced by keeping the amount of water and superplasticizer constant. Different mixtures were analysed by adding barite powder and fly ash at the rate of decreasing the PC. A total of 13 distinct mixtures were meticulously prepared: the H0 control mixture and the H1-H12 mixtures. Subsequent to this, samples were produced. The Portland cement used in each of the mixture produced was CEM I 42.5 R. The water-cement ratio was determined as 0.40 in the control sample mix. In the samples other than the control sample, the amount of PC was reduced and UK and barite powder (BT) were added in the same proportions and the water/binder ratio was 0.40. The fresh mortar mixtures prepared were then placed in moulds after the spreading diameter tests had been performed. After 24 hours the samples were remove from the mould, they were stored in laboratory curing tanks for 3, 28 and 90 days. The produced samples were then subjected to a series of rigorous tests. These included pressure, bending, high temperature resistance, ultrasonic pulse velocity, capillary water absorption and freeze-thaw tests, which were conducted at the specified ages. For the purposes of these tests, 195 beam samples with dimensions of 40x40x160 mm and 78 cube samples with dimensions of 50x50x50 mm were produced. Following the conduction of the tests, it was determined that the control sample designated H0, which comprised solely BA+PC, exhibited higher strength in comparison to the vast majority of the other mixtures. The samples containing BA+BT+PC were found to exhibit higher strengths in comparison to the mixtures containing BA+BT+UK. Following a collective evaluation of all test results, it was determined that the H1 sample containing BA+ 5 BT +95 PC was the mixture with the most optimal proportions.