Influence of Metakaolin on Properties of Concrete Modified With Polycarboxylate Admixture for Rigid Pavement Repair

Abstract

Abstract. The effect of partial cement replacement with high-activity metakaolin on the strength, frost resistance, shrinkage and abrasion resistance of concrete modified with polycarboxylate admixture MasterGlenium SKY 608. Portland cement CEM II/A-S 42.5 (ПЦ II/А-Ш-500) with partial metakaolin replacement 15 kg (3.75 %) and 30 kg (7.5 %) was used for concrete preparation. The amount of superplasticizer in all studied compositions was 1.2% of cement weight. Slump of concrete mixtures was 6…7 cm. It was found that with increasing amount of metakaolin W/C ratio of mixtures increased slightly. The early compressive and flexural strength (at the age of 2 days) of the composition without metakaolin was higher than similar indicators with partial cement replacement with the active mineral admixture. It is worth noting the positive effect of increasing the metakaolin amount on early strength, because the composition with 30 kg metakaolin had strengths higher at 2 days of in difference to the composition with 15 kg metakaolin. It is necessary to note high frost resistance of all obtained concretes. Its grade of frost resistance reached F200 (evaluated according to the method for road concrete), which is equivalent to the grade F600 for structural concrete. Abrasion resistance was in the low range (0.30-0.31 g/cm2), total shrinkage does not exceed 0.28 mm/m, which in combination with high frost resistance has a positive effect on the durability of concrete mixtures for rigid pavements repair.

Research of Strength, Frost Resistance, Abrasion Resistance and Shrinkage of Steel Fiber Concrete for Rigid Highways and Airfields Pavement Repair

“…To preserve the workability of concrete mixtures, MasterGlenium SKY 608 plasticizer was used in an amount of 1.2% of the cement content (4.8 kg/m 3 ). This percentage was determined as rational for repair concrete in preliminary studies [31,32].…”