Nano-modified cementitious composites with high volume supplementary cementitious materials incorporating basalt fiber pellets

Abstract

In this study, high performance nano-modified cementitious composites were developed. These composites incorporate 50% fly ash or slag (industrial by-products) replacement of the cement component, 6% nano-silica sol and a new type of basalt fiber strands encapsulated by polymeric resins termed as basalt fiber pellets. The fresh and mechanical properties were investigated for the developed composites with different dosages of basalt pellets (2.5%, 4.5% and 6.9% by volume). Generally, the slag based composites showed improved performance compared to the fly ash based composites. Although the compressive strength of the specimens was reduced with increasing the dosage of pellets, the flexural performance of the composites was significantly enhanced in terms of post-cracking behavior, residual strength and toughness. Composites comprising 4.5% and 6.9% pellets exhibited deflectionhardening behavior. Hence, they have a promising potential for many infrastructure applications.

A Review of the Combined Effect of Fibers and Nano Materials on the Technical Performance of Mortar and Concrete

“…BF is known for improving flexural behavior of reinforced concrete, besides a considerable elastic behavior facing exposure to elevated temperatures. Despite their remarkable independent performance, some studies were conducted to show the combined effect of using BF and NS together on the mechanical and durability properties of mortar and concrete [29,44,[51][52][53][54][55][56]. The addition of NS and BF together adversely affects workability; this observation is in agreement with previous studies [29,44], which shows that the slump of concrete reduces with an increasing of the BF and NS content.…”

“…According to studies [44,[51][52][53][54][55], as shown in Figure 1, the optimum compressive strength of concrete can be obtained by using 0.037-2% of BF and with a ratio of NS to BF between 15 to 30. Moreover, using recycled aggregate and BF without NS reduces the compressive strength up to 30%, while the addition of NS by 6% enhances compressive strength up to 16%.…”

“…In addition, flexural strength can be greatly affected by adding BF and NS to the cementitious mixes. For example, outputs of studies [29,51,52,[54][55][56] show that the proportion of fiber and NS in the mixes is the most effective factor in improving flexural strength in which it can be improved up to 30% by using 0.1-1% of BF while the ratio of NS/BF is in between 6 to 10 (see Figure 2). Nevertheless, increasing the content of NS by more than 3% adversely affects the flexural strength as shown in Figure 2.…”