Assessment of the Influence of the Type of Filler Materials on the Properties of Cement Grouts

Cement grouts have many purposes in various civil engineering applications such as precast construction, soil stabilization and structural rehabilitation. Using filler materials as a component in cement grouts has been increasingly implemented. The incorporation of such fillers not only does improve the fresh and hardened properties of grouts but also contributes to the decarbonization of grouts by reducing the amount of Portland cement, thereby lowering the carbon footprint of grouting materials. This study aims at assessing the influence of various filler materials on the properties of cement grouts. Three different fillers were used in this study: commercial limestone, commercial pure dolomite, dolomitic quarry dust. These fillers were assessed in terms of their effect on the spread, flowability, cohesion and compressive strength at 3, 7 and 28 days. The results show that fresh properties of the grout were dependent on the type of fillers. Dolomitic quarry dust improved the workability and flowability more than the commercial limestone and dolomite did. The compressive strengths of cement grouts did not change significantly with the incorporation of the fillers. However, cement grout samples including quarry dust exhibited slightly higher 28-d compressive strength than other samples although the same mix had lower 1-d compressive strength than other mixes. This study highlights the benefits of utilizing quarry dust in cement-based binders without compromising the performance.

Experimental Investigation on Geopolymer Concrete with Various Sustainable Mineral Ashes

The aim of this research was to find the best alternative for river sand in concrete. In both geopolymer concrete (GPC) and cement concrete (CC), the fine aggregates are replaced with various sustainable mineral ashes, and mechanical and durability tests are conducted. Specimens for tests were made of M40 grade GPC and CC, with five different soil types as river sand substitute. The materials chosen to replace the river sand are manufactured sand (M-sand), sea sand, copper slag, quarry dust, and limestone sand as 25%, 50%, 75%, and 100%, respectively by weight. GPF50 and CC50 were kept as control mixes for GPC and CC, respectively. The test results of respective concretes are compared with the control mix results. From compressive strength results, M-sand as a fine aggregate had an increase in strength in every replacement level of GPC and CC. Additionally, copper slag is identified with a significant strength reduction in GPC and CC after 25% replacement. Copper slag, quarry dust, and limestone sand in GPC and CC resulted in considerable loss of strength in all replacement levels except for 25% replacement. The cost of GPC and CC is mixed with the selected fine aggregate replacement materials which arrived. Durability and cost analyses are performed for the advisable mixes and control mixes to have a comparison. Durability tests, namely, water absorption and acid tests and water permeability and thermal tests are conducted and discussed. Durability results also indicate a positive signal to mixes with M-sand. The advisable replacement of river sand with each alternative is discussed.

EFFECTS OF VARYING WATER-CEMENT RATIOS ON DIFFERENT GRADES OF CONCRETE USING LOCALLY MATERIALS

This research focused on laboratory tests that was conducted using locally available 10mm washed all-in gravel, quarry dust with varying water cement ratio. The research was carried-out using 108 (150 x 150 x 150) mm standard cubes that were all tested from three designed concrete mixes. In the present study, the role of water-cement ratio in compressive strength of concrete was investigated. The mixed concrete samples with water-cement ratios of 0.3, 0.35 and 0.40 were experimented for 3, 7, 21 and 28 days of curing. The results of compressive strength experiment showed that due to increase in water-cement ratio from 0.3 to 0.40, the compressive strength improved from 22 N/mm2 to 24.33 N/mm2 for 1:1.5:3 design mix, the compressive strength improved from 22.88 N/mm2 to 24 N/mm2 for 1:2:1 design mix, while compressive strength improved from 24 N/mm2 to 25.3 N/mm2 for 1:1:2 design mix respectively. The results for compressive strength experiments showed that the 0.4 water-cement ratio resulted in the optimum compressive strength for all three design mixes.

Mechanical Performance of High-Density Polyethylene (HDPE) Composites Containing Quarry Dust Filler

An innovative thermoplastic composite was produced using quarry dust which is an industrial waste from quarry industries. The quarry dust was added into high-density polyethylene (HDPE) using melt blending technique in an internal mixer at different mixing loading ratios. The quarry dust filled HDPE (QD-HDPE) composites were then characterized in terms of morphological and mechanical properties. Analysis on processing torque to produce QD-HDPE composites was conducted and the results showed that the optimum quarry dust loading in HDPE composites is at 30wt%. The results from mechanical test such as ultimate tensile strength (UTS), E-modulus, elongation at break, and flexural strength justify this. Scanning Electron Microscopy (SEM) analysis shows that quarry dust had a rough surface with sharp edges and it can be successfully added into HDPE matrix as a filler. In conclusion, performance of the HDPE composites is enhanced by the incorporation of quarry dust. This indicates that quarry dust is a potential filler to be used in thermoplastic composite industries in order to reduce the production cost and relax the pollution problems.