Properties of Lightweight Self Consolidating Concrete

点击翻译按钮获取中文摘要

Lightweight (LWC) and self-consolidating concrete (SCC) are finding widespread use in the construction industry. SCC is a highly flowable, high-performance concrete that spreads readily under its own weight without the use of vibrators and achieves the desired consolidation. LWC has been used in many different applications and is known for its performance and durability. While the economic, practical and technical benefits of both are well known, combining LWC and SCC might lead to serious problems in flowability and self-compactability due to the difference in density between lightweight aggregate and normal weight sand. The objective of this proposal is to investigate the rheological (flow characteristics), mechanical, structural, durability and shear performance of a range of lightweight self-consolidating concrete (LWSCC) mixtures. Numerous studies have been performed on SCC and LWC but there is a lack of data on the properties of LWSCC. Therefore there is a need for theoretical and applied research to help develop a LWSCC that combines the advantages of structural LWC (reduced dead loads, high insulation capacity, improved durability, resistance against fire and chemical attack) with SCC properties that offer good filling and passing ability with high segregation resistance. The LWSCC mixtures proposed will contain metakaolin, silica fume, fly ash, and/or binary blends of these as a supplementary cementing material. Pumice, expanded shale, and/or artificial lightweight aggregate will be used as a replacement of coarse aggregate in order to reduce the mass of concrete. The LWSCC mixtures will be tested for fresh (flowability/filling ability, viscosity/ flowability, passing ability, and segregation resistance) and hardened (compressive strength) properties. The research outcome - a better performing, next generation LWSCC, will expand our knowledge of LWSCC and make a significant impact on its future application in the Canadian concrete production and construction industries. The program has the potential to make impacts both on the environment through reduced size of structures such as bridges and reduced materials needs; and on the competitiveness of Canada's concrete industry.