Studying concrete porosity and absorption is very important for determining the
compatibility and durability of concrete repair materials. The objectives of this research
were: to know the absorption, porosity and compatibility of various repair materials, to
know the extent of protection given by various repair materials on concrete based on the
measurement of absorption and porosity. Percent of absorption and porosity were
measured according to ASTM C642-06. Scanning Electron Microscope analysis was
conducted to study the porous and bond behaviour of concrete with repair materials.
Absorption and porosity rate were determined based on ASTM C 1585-04.
The result showed that UPR-Mortar 50 % repair material had the lowest absorption and
porosity measurements indicating that it provided sufficient protection. This repair material
is compatible based on porosity and absorption, but incompatible based on bond strength
because it had weakest bond with concrete when exposed to temperature. The highest
measurement values for absorption and porosity were found for concrete with normal
mortar repair material indicating that it did not provide sufficient protection. This repair
material was compatible based on bond, but incompatible based on porosity and
absorption.
Based on Scanning electron microscope analysis, normal mortar repair with normal
concrete had more pores but with strongest bond whereas UPR-mortar 50% repair material
had weak bond after exposed to high temperature but lowest pores. The peculiar feature of
this research is that better bond compatibility between repair materials and concrete does
not guarantee good protection from absorption and porosity. Materials with weak bond
strength can surprisingly have protection from concrete absorption and porosity.
Keywords: Absorption, Compatibility, Concrete, MS, Porosity, Protection, Repair
materials, SEM