THE EFFECT OF POLYVINYL ALCOHOL FIBER ON THE MECHANICAL PROPERTIES OF HIGH STRENGTH GEOPOLYMER CONCRETES

Today, it is quite common to use

conventional Portland cement-based concrete in buildings. Geopolymer concrete has been proposed as an

alternative to Portland cement concrete due to the high greenhouse gas effect

and the environmental pollution of energy consumption caused by cement

consumption. In this study, metakaolin and ground blast furnace slag (GBFS) were

preferred as binder materials to increase the early age strength of concrete

and not cause loss of strength due to possible porosity in later ages. In addition, due to the high

probability of brittle fracture of geopolymer concrete after curing at high

temperatures, it aims to cope with these negative properties by using polyvinyl

alcohol fibers (PVA) without reducing the flexural, compressive strengths of

concrete. In this study, to examine the effect of PVA on the mechanical properties

of high strength geopolymer concrete, three mixtures were designed, 0.3% kg/m3,

0.6 kg/m3 fiber and did not contain any fibers which were kept in a

curing environment at 80 oC for 10 hours. GBFS and quartz powder vary, with the

same weight percentage of metakaolin as the binder in the mixtures. In addition, the aggregate (quartz)

and alkali activator contents of the mixtures are the same. The test results showed that the

mixture containing 0.6 kg/m3 PVA reached 136.2 MPa by increasing the

compressive strength by 18.77% compared to the without PVA mixture, and

reaching 6.03 MPa by increasing the flexural strength by 63.41%. In addition, it has been determined

that the use of PVA as a reinforcing element prevents brittle fracture in

geopolymer concrete samples. The results showed that PVA could be used as a

reinforcement element to prevent the negative behavior of geopolymer concrete,

such as high mechanical properties and less energy consumption and prevent its

negative behavior, such as a brittle fracture.<o:p></o:p>