The Application of Novel Cements in Concrete Block Manufacturing Towards Low Carbon-High Strength Masonry

点击翻译按钮获取中文摘要

We propose to develop new cements for concrete block production with much less associated Greenhouse gas emission and with higher strength. Normal strength blocks manufactured with the novel cements will have much lower associated GHG than the stronger blocks. The novel cements will be produced by using supplementary cementitious materials which include reactive metakaolin and a seeding material to encourage the production of calcium-(alumino-)silicate-hydrate, the primary binding phase in cement paste, with specific properties. Recognizing that nano-cements produce very high strength, grinding the novel cements to a much smaller average size will produce high strength concretes. There are two main objectives of the research. The first is to determine concrete mixes with novel cements that can replace current production and thereby reduce the greenhouse gas emissions associated with "standard" concrete block masonry. The second is to use novel cements to produce high strength blocks that can be used to build bigger and stronger structures from concrete blockwork and thereby expand the use of masonry, and reduce construction costs. This may require the formulation of a mortar compatible with the high strength block to achieve high strength masonry. In addition, taking full advantage of the new blocks could be limited by the current restrictions on tall wall design in the Canadian masonry standard. Recent work has shown that the way tall walls are designed following the procedure in the current standard is very conservative and not very accurate compared to test results or other standards around the world. Therefore there is a need to examine the methods used in the current standard and determine how to update them so they allow more effective use of masonry in general, but in particular, they encourage full and effective use of the high strength blocks in the construction of tall walls. The proposal is supported by the Canadian Concrete Masonry Producers Association whose members will benefit from the ability to market both "greener" and stronger concrete blocks. The Canada Masonry Design Centre also supports the application and will benefit through increased work for its contractor members.