23-05-2012, 11:42 AM
PROPERTIES OF GREEN LIGHTWEIGHT AGGREGATE CONCRETE
PROPERTIES OF GREEN LIGHTWEIGHT.pdf (Size: 1,001.38 KB / Downloads: 161)
Introduction
Most of normal weight aggregate of normal weight concrete is natural stone such as
limestone and granite. With the amount of concrete used keeps increasing, natural
environment and resources are excessively exploited. Synthetic lightweight aggregate
produced from environmental waste, like fly ash, is a viable new source of structural
aggregate material. The use of lightweight concrete permits greater design flexibility
and substantial cost savings, reducing dead load, improved cyclic loading structural
response, longer spans, better fire ratings, thinner sections, smaller size structural
members, less reinforcing steel, and lower foundation costs [1-3]. Weight of
lightweight concrete is typically 25% to 35% lighter but its strengths is comparable
to normal weight concrete.
This paper discusses the mechanical properties of a newly developed structural
lightweight aggregate which is made from expanded clay. The aggregate is
reinforced with a PFA rich surface coating applied at a later stage of firing. The
International Workshop on Sustainable Development and Concrete Technology
experience of utilizing this green lightweight aggregate concrete in the
prefabrication of structural element is also presented.
Experiments and Results
. Characteristics of the aggregate
The quality of the green aggregate [in terms of crushing strength] was specified by a
crushing strength test based on GB2842-81 (China Standard). The strength as
measured by compressing the aggregate in a steel cylinder through a prescribed
distance of 20 mm is 3.8 MPa. Results of the sieve analysis and water absorption of
the aggregate at different time
Conclusions
The successful application of structural lightweight aggregate demonstrated that
lightweight used for precast structural elements can be used in building construction
to increase the speed of construction, enhance green construction environment such
as reducing the wet trade on site and keep dust level at construction site to the
minimum.