Effect of Slate Powder on Mineral Admixtures in Suppressing Alkali-Silica Reaction of Slate Aggregate

In order to study the effects of slate powder on mineral admixtures in suppressing ASR of slate aggregate, refer to the following methods: accelerated mortar bar test in "Standard for Constructional Quality Acceptance of Railway Concrete Engineering" TB10424-2010 and "Durability Design of Railway Concrete Structures" TB10005-2010, as well as an improved steam curing method. The text has studied the expansion of the specimens that are made from slate aggregate with different powder contents and specimens using slate powder as admixtures. The results show : When powder content in aggregate is less than 20%, it dose not have adverse effects; ASR of high-activity slate aggregate can be suppressed by using 30% fly ash and 5% silica fume as mineral admixtures; when the mineral admixtures are effective, a certain amount of powder mixed with admixtures can contribute to suppression; the main mechanism that slate powder can suppress ASR is that alkali in concrete can be consumed and physically diluted by slate powder.