Properties and durability of self-compacting concrete incorporated with nanosilica, fly ash, and limestone powder

This research focused on finding the effect of nanosilica (NS) on the properties of self-compacting concrete (SCC). NS in various proportions of 1%, 2%, 3%, 4%, 5%, 6%, 8%, and 10% was added to SCC with 10% silica fume (SF) or 10% fly ash (FA) by weight of cement to improve the properties of SCC. While the limestone powder (LSP) was used at a fixed supplementation of 15% by cement weight for all mixes. Fifteen SCC mixtures were designed based on the European guidelines for self-compacting concrete. The properties of fresh SCC were evaluated by several tests of the slump flow, slump T-50, V-funnel, V-funnel T-5min, L-box J-ring, and fill box. Meanwhile, several tests evaluated SCC's mechanical properties, including compressive strength, split tensile strength, flexural strength, bond strength, and modulus of elasticity. Moreover, the permeability properties of SCC were evaluated by water permeability and air-content tests. The effect of applying high temperatures (100-800 degrees C) on the compressive strength of SCC containing NS with cementitious materials (SF, FA, and LSP) was also evaluated. Results showed that adding 3% NS with 10% SF and 15% LSP by weight of cement can be used to achieve the best mechanical properties of SCC. The SFNS3 mixture achieved the highest mechanical properties of 75.1, 11.9, and 41,300 MPa for compressive strength, bond strength, and modulus of elasticity tests. While the results for the slump flow, slump T-50cm, and fill box were 680 mm, 6 s, and 93%.