Title : “Polymer Fiber: A Potential Admixture of Cement for Concrete
Mixes"
Researchers : Glen F. Calatrava, Merlito L. de Luna and Ma. Milagrosa L. Tarrayo
Adviser : Engr. Elizabeth R. Rivera
School : FEATI University
Date : March 2005
Degree : Bachelor of Science in Civil Engineering
This study covers the experimentation of adding polymer fiber into the concrete mix before mixing. Mix proportion used was with respect to the cement’s percent by weight in kg being an admixture only. The experiment consists of eighteen specimens: five experimental groups with varying proportions of polymer fiber to cement and a standard mix having no polymer fiber, each being poured and molded in three cylinders for different curing ages. Testing the specimens is classified according to the curing age of the concrete as on the seventh, fourteenth and twenty-eighth days.
This polymer concrete is applicable to specific structural members such as slab overlay, asphalt overlay, or bridges being subjected to heavy moving loads
This study has been made to determine the possibility of using polymer fiber as a potential admixture of cement in a concrete. Also, to further analyze polymer fiber and it’s various structural applications that would greatly contribute to the construction industry. The experiment made was formed by mixing dissolved polymer fiber (polyvinyl alcohol, pva) into the cement, sand, and gravel at 1:2:4 mix proportion of class “A”. The polymer fiber being added into the concrete mix has five different proportions ranging from 2% to 10% with respect to the cement’s weight in kg. These concrete mixes were molded in a cylinder, and then cured for seven, fourteen and twenty-eight days. After curing at specified days, the specimens were subjected to compressive strength test with the use of the hydraulic press. Based on the compressive strength test results, the specimens were noted that polymer fiber mix gives better strength than the standard mix up to 50% at the proportion 6% to 94%, polymer fiber to cement, respectively. It has also been found and observed that the greater the polymer fiber, the more viscous is the mix, which makes it non-workable to mix.
SUMMARY OF FINDINGS AND CONCLUSION
On the basis of the compressive strength test results and physical observations, the conclusion that, it is possible to add polymer fiber (polyvinyl chloride) as a cement admixture for concrete mixes showing greater strengths over the standard mix have been made.
Besides, it gives the following consequences:
The proportion 2% of polymer fiber & 98% of cement by weights gave the highest compressive strength results while proportion 6% of polymer fiber & 94% of cement gave equal strength to the standard mix. Polymer fiber being added to the cement as an admixture gave efficient characteristic on the performance of the concrete with respect to its properties as to better strength, durability, elasticity and shrinkage. Concrete may adopt the plastic’s property in terms of elasticity itself. Giving higher strength results, which tend the concrete to deform but would certainly return to its original shape as unloaded.
RECOMMENDATION
The experiments performed in this study were primarily designed to get the relative advantages and disadvantages of the polymer fiber over the standard mix specimens. For further study, the following recommendations are given Polymer fiber to be added to the concrete mix must be based on the constant volume of cement, sand and gravel at certain mix proportion, so that greater strengths may be reached. Aggregates to be used should be analyzed first with respect to its properties as to grain size analysis, fineness modulus, specific gravity, and moisture content in order to produce more accurate concrete mixes. Additional tests such as splitting tensile strength, flexural strength and shrinkage crack mitigation should also be performed for more evidences of comparison for the experiment. Specimens should also be weighed so as to compare polymer fiber mix over standard mix to further prove plastic’s lightweight property.
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