An analysis of the abaca natural fiber in reinforcing concrete composites as a construction material in developing countries

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1988

OSTI ID:6836868

Magdamo, R V

This study analyzed the flexural and splitting tensile strengths and the ductility of abaca fiber-reinforced concrete composites. Abaca fibers are natural fibers of vegetable origin from the abaca plant native to the Philippine Islands. The purpose was to investigate how various volume-fractions of the abaca fiber could affect the mechanical properties of the concrete matrix. A concrete design mix containing a volume ratio of 1.0 part Type I Portland cement and 3.0 parts sand was used in the preparation of laboratory test samples. Abaca fibers were 1 to 1.5 inches long and randomly mixed with the concrete at 0.2% and 0.4% volume fractions. The fibers were not chemically treated and no admixtures were used. Samples were cast into concrete cylinders and flexural beams. Standard ASTM procedures in casting of flexural beams and concrete cylinders and the curing of 28-day concrete samples were followed. The center-point loading method of the flexural test and the splitting tensile test was utilized. Addition of abaca fibers decreased the mean flexural and splitting tensile strengths of the concrete matrices. However, ductility of the matrices increased with the addition of abaca fibers at 0.2% and 0.4% volume-fractions. The Scanning Electron Microscope (SEM) micrographs revealed that increasing the fiber volume-fraction influenced the growth rate of dehydration precipitates as CH (calcium hydroxide) crystals. At the 0.2% volume-fraction, smaller density of precipitates grew into large crystals, while at the 0.4% volume-fraction, the dehydration precipitates were much more dense, which were made up of small sized crystals. Abaca fibers in the concrete mix decreased the mean flexural and splitting tensile strengths, increased the modulus of elasticity, improved the ductility, and acted as a medium to slow down and stop the propagation of cracks.

• Research Organization: University of Northern Iowa, Cedar Falls, IA (USA). Dept. of Mathematics
• OSTI ID: 6836868
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360601* -- Other Materials-- Preparation & Manufacture
360603 -- Materials-- Properties
BUILDING MATERIALS
CONCRETES
DEVELOPING COUNTRIES
DUCTILITY
FIBERS
FLEXURAL STRENGTH
FOOD
MATERIALS
MECHANICAL PROPERTIES
PLANTS
REINFORCED CONCRETE
REINFORCED MATERIALS
RESOURCE ASSESSMENT
TENSILE PROPERTIES
VEGETABLES