12-09-2014, 02:59 PM
Preparation and properties of porous aerated concrete
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EXPERIMENTAL PROCEDURE
Raw materials for AAC production are listed in Table 1 and their functions are
discussed as follows. Ideal sand contains silica, SiO2, which is one of the important
components in production of AAC. It is preferred to have 90 % or above SiO2 in the
production of AAC but requires minimum of 85%. Autoclaved products (AAC) preferably
contain a crystallized form of silica, e.g. quartz, which helps to increase the crystallinity of
the calcium silicate hydrate formed in the autoclave. The specific surface area of the silica
is important. In most cases the silica sand is grounded to the required fitness by ball
milling. Finer sand reduces the processing time, decreases the degree of crystallization,
and increases the compressive strength. Cement with higher surface area will h
RESULTS AND DISCUSSION
AAC blocks obtained have many useful properties as: lightweight (about a fifth the
weight of concrete), non-combustible, unique thermal properties (because of its cellular
structure), exceptional sound absorbing characteristics, a vapor permeable and
breathable wall system. They are a lot like wood and a pollution free manufacturing
process (that makes best use of a minimum amount of energy and natural resources,
resulting in a premier green building material). The material's lower weight also makes it
easier to transport. Table 2 shows the properties of some of the Aerated Autoclaved
Concrete blocks that were made.
CONCLUSION
In this work we have presented the potential benefits of using of Aerated Autoclave
Concrete, laboratory method of preparation and some preliminary data on properties of
the materials. Furthermore, chemical reactions involved in the process are not well
understood, in particular reactions in the autoclave step. Changes to raw materials,
reduction in the processing time, increase in the strength of the materials and reduction in
the cost of production are the main objectives of our current research focus of this project.
Due to the growing demand of AAC, we anticipate this work will draw significant interests
from many companies, consultants and municipalities of UAE, Bulgaria and other
countries.