Location
University of Leeds
Keywords
Nano-Silica; Blended Cement; Natural Pozzolan; Durability
Abstract
In the present study, the mechanical properties and durability of blended cement mortars containing nanosilica and natural pozzolans is investigated. Trass and pumice, two different Iranian natural pozzolan, are used in the experiments. For cement blends preparation, nano-silica replacement levels of 2, 3 and 4% by mass of cement was considered; each mixture contained one of the natural pozzolans with a fixed replacement percentage of 15. The Standard mortar samples were made with w/cm ratio of 0.485; the flow of all mortars ranged from 14 to 16 cm. All prepared mortars’ samples were cured in saturated limewater until the test ages. The electrical resistivity, chloride permeability, capillary absorption, and compressive strength tests were performed on mortar samples in accordance with the standards. Generally, the results indicated significant improvement in durability parameters of mortars containing both nano-silica and natural pozzolan. Furthermore, it was observed that nano-silica can improve the strength development of natural pozzolan mortars and compensate the reduction in the initial compressive strength of natural pozzolans mortars. The blend containing 4% nano-silica and 15% Trass, was found to have the best performance from the view point of durability characteristics and compressive strength at all test ages.
Transport properties and strength development of Blended Cement Mortars Containing Nano-Silica
University of Leeds
In the present study, the mechanical properties and durability of blended cement mortars containing nanosilica and natural pozzolans is investigated. Trass and pumice, two different Iranian natural pozzolan, are used in the experiments. For cement blends preparation, nano-silica replacement levels of 2, 3 and 4% by mass of cement was considered; each mixture contained one of the natural pozzolans with a fixed replacement percentage of 15. The Standard mortar samples were made with w/cm ratio of 0.485; the flow of all mortars ranged from 14 to 16 cm. All prepared mortars’ samples were cured in saturated limewater until the test ages. The electrical resistivity, chloride permeability, capillary absorption, and compressive strength tests were performed on mortar samples in accordance with the standards. Generally, the results indicated significant improvement in durability parameters of mortars containing both nano-silica and natural pozzolan. Furthermore, it was observed that nano-silica can improve the strength development of natural pozzolan mortars and compensate the reduction in the initial compressive strength of natural pozzolans mortars. The blend containing 4% nano-silica and 15% Trass, was found to have the best performance from the view point of durability characteristics and compressive strength at all test ages.
