EFFECT OF CURING ON THE PROPERTIES OF POLYMERIC CONCRETE

Limestone and clay are the prime raw materials used in the manufacturing of
Portland cement and quarrying of them is becoming the source of environmental
degradation. Research showed that in near future limestone will be hardly available
for cement production. Besides that, carbon footprints due to cement production are
causing global warming. In addition to this, waste disposal is also becoming a global
issue because of scarcity and expensiveness of landfills. Polymeric concrete utilizes
waste materials such as fly ash (FA), rice husk ash and silica fume (SF) together with
alkaline solution (NaOH & Na2SiO3), to form a green binder to replace cement which
is the primary objective of this research. Secondly, this research study focuses on
complete elimination of Portland cement for production of concrete that can achieve
28 days cube strength in the range of 40-50 MPa with the emphasis on the curing
techniques applicable for in-situ construction namely; hot gunny sack, ambient and
external exposure curing. This research study incorporates FA as a base source
material and microwave incinerated rice husk ash (MIRHA) or SF. The replacement
levels were kept at 3%, 5% and 7% of FA.
In addition to tests for compressive, tensile and flexural strengths, scanning
electron microscopy analysis was also performed to study the microstructure of
polymeric concrete. Results showed higher compressive and tensile strengths values
for external exposure curing as well as better development of microstructure for the
same, compared with other types of curing. Flexural strength was also much better as
compared to OPC concrete.
Keywords: Polymeric concrete, Fly ash (FA), Microwave incinerated rice husk
ash (MIRHA), Silica fume (SF), Scanning electron microscopy (SEM)