Granite rock fines addition and its effects on self-compacting mortars’ properties

Abstract The present study evaluates the use of granite rock fines (GRF) in self-compacting mortars, aiming to obtain adequate rheological characteristics without incorporating viscosity modifying additives. For this, mini Funnel-V, mini Slump Test and physical-mechanical characterization tests were carried out on reference mortars (without GRF) and with GRF substitution levels equal to 5%, 15% and 25%, to cement’s volume. The hydration of the pastes of these mortars was also evaluated using the isothermal calorimetry technique. Subsequently, the theoretical porosity of the pastes was analyzed through the compactness test, in order to obtain the interparticle spacing (IPS) of these pastes. When incorporating GRF, the viscosity of the mortar was adjusted, increasing the flow time by up to 4.3 sec, reducing cement consumption by up to 12% and, consequently, the release of heat during hydration. Furthermore, it was concluded that the incorporation of GRF reduces the porosity of mortars by up to 17.63% and increases the compressive strength by about 11% as a result of the addition of 15% FRG. However, due to the fact that the distance between the particles of the paste is reduced, the consumption of superplasticizer additive content has been increased to achieve the ideal spreading.

摘要 本研究评估了花岗岩岩粉（granite rock fines, GRF）在自密实砂浆中的应用价值，旨在无需添加增粘剂即可获得适宜的流变性能。为此，针对基准砂浆（未掺加GRF）以及以水泥体积为基准、替代率分别为5%、15%和25%的掺GRF砂浆，开展了微型V漏斗试验、微型坍落度试验与物理力学性能表征试验。同时采用等温量热技术对上述砂浆浆体的水化过程进行了测试分析。后续通过密实度试验分析浆体的理论孔隙率，以获取浆体的颗粒间距（interparticle spacing, IPS）。研究结果显示，掺入GRF可调节砂浆粘度，使流动时间最长延长4.3秒，同时将水泥用量最多降低12%，进而减少水化过程中的热释放量。此外，本研究得出结论：掺入GRF可使砂浆孔隙率最多降低17.63%；当GRF掺量为15%时，砂浆抗压强度可提升约11%。但由于浆体颗粒间距缩小，为达到理想扩展度，需提高高效减水剂的掺加量。