EffectofMetakaolin and Nano-SiO2onshort and Long-term shrinkageofself-compactingcement sandmortar

The use of cementitious products isincreasing in the world,Thusreplacement part of cement with pozzolanic materials reduced energy consumption and preserve natural resources and the environment and also improve the mechanical properties and durability of the cement mortar.Furthermore Nano technology has promptedto tremendous developments in technology of building materials in recent yearsso use of nano-silica has considered by many researchers.On the other hand the use of self-compacting mortar due to high performance and flow ability has increased remarkable in recent years. One of the major issues affecting on durability of cement products is shrinkage of cement mortar.Because of the importance of self-compacting mortar and role of additives pozzolanic, particularly at the nanoscale, in this laboratory study the binary blend of Metakaolinpozzolan and Nano-SiO2as replacement part of the cement have been used. The rate of shrinkage of self-compacting mortar has been investigated.Therefore Metakaolin with percent by weight 10, 15 and 20 and Nano-SiO2with percent by weight 1% and 2% were replaced cement. The results show that using metakaolin,Nano-SiO2 and combination of them reduce the rate of shrinkage of self-compacting cement mortar.