Rheological and Mechanical Properties, Acid Resistance and Water Penetrability of Lightweight Self-Compacting Concrete Containing Nano-SiO_2, Nano-TiO_2 and Nano-Al_2O_3

摘要

This paper presents rheological and strength properties, acid resistance and water penetrability of lightweight self-compacting concrete (LWSCC) containing nano-SiO2(NSi), nano-TiO2(NTi) and nano-Al2O3(NAl) as a partial substitute of cement. For this aim, one part of cement was replaced by 2 and 4 wt% of NSi, 2 and 4 wt% of NTi and 1 and 2 wt% of NAl. In addition, the rheological properties of LWSCCs were quantitatively evaluated by slump flow diameter, V-funnel flow time, J-ring, U-box and L-box height ratio. Then, the mechanical properties of LWSCCs were evaluated by compressive and splitting tensile strength tests at 3, 7 and 28 days of curing, while the water penetrability of LWSCC samples was evaluated by the water permeability test. The specimens were exposed to 5% sulfuric acid solution up to the age of 70 days, and the corrosion was identified in terms of mass loss and retained compressive strength. It was also found that all the LWSCCs containing nanoparticles show a good behavior in terms of deformability, passing ability and resistance to segregation. Results indicated that the incorporation of nanoparticles can improve the compressive strength, acid resistance and water penetrability of LWSCCs. In addition, the SEM tests revealed that the microstructure of LWSCCs with nanoparticles was more homogenous and compact than that of the control samples.