DEVELOPMENT OF REACTIVE POWDER CONCRETE WITH LOCAL MINERAL ADMIXTURES AND INVESTIGATION OF ITS ALKALI-SILICA REACTIVITY
Project no. 781 · Status: Kapanmış · 2016
Summary
Reactive powder concrete (RPC), is an ultra-high performance concrete type with superior mechanical, ductility and durability properties. RPC is designed by optimizing the gradation of its solid ingredients and obtaining the maximum density by particle packing models. The objective of this study is design and production of RPC by gradation optimization models and incorporating various types of mineral admixtures such as silica fume, fly ash, glass powder, pumice powder and granulated blast furnace slag. The compressive strength of these mixtures after curing by various methods and also alkali-silica reactivity (ASR) were the investigated properties. At the design stage of the study, the ideal particle size distribution curves suggested by Fuller and Andreasen and Andersen were taken as reference. RPC mixtures included quartz and basalt aggregates having maximum aggregate size of 2 mm. Three different curing methods applied in the study included 28-day standard water curing, 1-day 20°C water+1-day 60°C hot water curing and autoclaving. After these curing processes, compressive strength of the mixtures was determined. At the last stage of the study, some of the RPC mixtures were exposed to RILEM AAR-4.1 accelerated concrete prism test and the expansion due to alkali-silica reaction was periodically determined. Some of the specimens exposed to ASR test were analized by SEM (Scannig Electron Microscope), EDS (Energy Dispersive Spectrometry) and TGA (Thermogravimetric Analysis) to detect their microstructural properties. The maximum compressive strength values obtained in the study belong to pumice powder+silica fume (171 MPa) and silica fume (170.5 MPa) incorporating mixtures designed according to Andreasen-Andersen model and having q=0.20 distribution parameter. ASR test results showed that all reactive powder mixtures prepared in the study had lower ultimate expansion than RILEM standart limit. Keywords: reactive powder concrete, mineral admixture, compressive strength, particle-packing models, alkali-silica reaction.