CONTRIBUTION OF FIBERS TO CRACK REDUCTION OF CEMENT COMPOSITES DURING THE INITIAL AND FINAL SETTING PERIOD

The contribution of steel, synthetic, and cellulose fibers to the shrinkage-crack reduction potential of cement composites during the initial and final setting period and its evaluation are presented in this paper. The primary variables of the investigation were: fiber type, matrix composition, and test methods. Fiber type consisted of steel and nonmetallic fibers (synthetic and cellulose) of varying lengths. The matrix consisted of cement mortar with various cement-sand ratios, concrete containing coarse aggregates, and lightweight concrete. In the case of test methods, the primary variables were specimen thickness and plan dimensions of the test panels. Results indicate that both steel and synthetic fibers make a definite contribution to shrinkage crack reduction during the initial and final setting periods. The microfibers (pulp form) are more effective in rich cement mortars, whereas the longer fibers are more effective in lean mortars and concrete. None of the test methods available in the published literature are suitable for standardization in the present form. The primary drawbacks are attempting to induce cracks in plain matrixes at normal conditions in terms of temperature, humidity, and wind velocity and possible errors that can occur in the measurement of crack area.

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  • English

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  • Accession Number: 00664722
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Aug 9 1994 12:00AM