This research presents an empirical relationship between modulus
of elasticity with compressive strength concrete that is prepeard
from localized materials and containing several perecentages of
natural pozzolan (0 ,10 ,15, 20)% , also for tow cem
ent quantity
(350 ,400 ) Kg/m3 and for tow ages(28 ,90 ) day .Then comparing
the experimentally obtained result with the mechanical properties
calculated using the recommend relationship from the various
design codes. A new empirical relationship between elastic
modulus, and compressive strength for concrete containing natural
pozzolan is proposed.
According to the Syrian standard 3411 & European standard EN 197-1, Portland
pozzolana cements and Portland limestone cements can be produced by partial replacement
of pozzolan or limestone up to 35%. Despite of the economical, ecological and techn
ical
benefits of adding natural pozzolan and limestone powder, they are often associated with
shortcomings.
The objective of the study is to investigate the effect of adding natural pozzolan,
limestone powder or both on the mechanical strength development of the prepared cement
mortars. In the study, sixteen types of binders (one OPC, six binary and nine ternary
blended cements) with different replacement levels of natural pozzolan, limestone powder
or both have been produced. The development of the compressive and flexural tensile
strength of all mortar specimens has been investigated after 2,7,28 & 90 days curing,
respectively.
Test results revealed that there was a decrease in strength with increasing amounts of
natural pozzolan. In addition, there was found an increase in the early age strength with
adding limestone powder. The increase in compressive strength when adding both natural
pozzolan and limestone powder has also been noted. Further, based on the results obtained,
an empirical equation was derived to predict the mechanical strengths of binary & ternary
blended cement mortars with curing times. The influence of adding natural pozzolan,
limestone powder or both on some physical properties of binary and ternary blended
cements have been reported, as well.
