The Effect of Slate Powder on Fly Ash in Suppressing Alkali Activity of Slate Aggregate

Abstract

Slate has high alkali activity.When broken as aggregate, it produce high content of slate powder.In order to study the effect of slate powder on fly ash in suppressing alkali activity of slate aggregate and the possibility of making full use of the powder,we carried the experiment on rapid mortar bar method.The experimental results show that:1. When the content of slate powder is less than 15% , it has no adverse effect on fly ash in suppressing alkali activity of slate aggregate. When the content of slate powder is greater than 15%,it can increase the effect of suppression.2. For alkali-silica reaction,what really suppress it is the active SiO2 that comes from slate powder or fly ash.As long as the mineral admixture containing active SiO2 grinds fine to the fineness of cement particle, it can increase the effect of suppression on fly ash in suppressing alkali activity of slate aggregate, rather than reduces the suppressive effect.

Effect of Different Activators on Rheological and Strength Properties of Fly Ash‐Based Filling Cementitious Materials

“…In the physical excitation mode, the particle size of fly ash is changed by mechanical milling technology, so its particle fineness is improved, and specific surface area is increased, which facilitates the dissolution of elements such as SiO 2 and Al 2 O 3 and the penetration of Ca 2+ , thereby improving the activity of fly ash [10,11]. As for the chemical excitation mode, different fly ash excitants are added to stimulate the internal potential activity of fly ash [12]. Fu et al [13] developed a compound additive and its ratio to effectively activate fly ash by using the methods of orthogonal design and uniform design and working out a computer program.…”