Fiber Reinforced Concrete 1990

The present state of development of the mechanics for fiber reinforcing of portland cement concrete by metallic, glass, plastic, and natural fibers is reviewed along with techniques for mixing and mix proportioning, placing, finishing, and actual and potential applications.

4032
Al-Tayyib, A-H. J., and Al-Zahrani, M. M.
"CORROSION OF STEEL REINFORCEMENT IN POLYPROPYLENE FIBER REINFORCED CONCRETE STRUCTURES"
ACI Materials Journal, Mar-Apr 1990, Vol. 87, No. 2, pp 108-113.

Adding polypropylene fibres (0.2% by volume of concrete) to concrete mixes enhances the properties of both fresh and hardened concretes. This paper presents results of an investigation of the effect of polypropylene fiber reinforcement in retarding the corrosion of reinforcing steel in concrete, as a result of improving the durability performance of the concrete embedding the steel reinforcement. Reinforced concrete slabs of different water-cement ratios of 0.45, 0.55, and 0.65, made with and without polypropylene fibers, were subjected to severe corrosion-initiating conditions and their resistance to corrosion was monitored for a period of more than 7 months. The effect of adding polypropylene fibers was also studied on some properties of the concrete that closely relate to corrosion of reinforcing steel. These include electrical resistivity, water absorption, and permeability of concrete. The results indicate polypropylene fiber reinforcement has no noticeable effect in retarding corrosion of reinforcing steel in concrete. The results of the electrical resistivity, water absorption, and permeability tests also do not show any significant improvement due to the inclusion of polypropylene fibers.

4033
Al-Tayyib, A-H. J. and Al-Zahrani, M. M.
"USE OF POLYPROPYLENE FIBERS TO ENHANCE DETERIORATION RESISTANCE OF CONCRETE SURFACE SKIN SUBJECTED TO CYCLIC WET/DRY SEA WATER EXPOSURE"
ACI Materials Journal, Jul-Aug 1990, Vol. 87, No. 4, pp 363-370.

This paper presents results of a testing program in which the effects of addition of polypropylene fiber to concrete mix and adequate concrete curing in enhancing the deterioration resistance of concrete surface skin subjected to cyclic wet/dry seawater exposure were evaluated. The results indicate that the addition of polypropylene fibers effectively retards the deterioration process of the surface skin of the concrete specimens cured in hot weather environment. Tests were carried out on 30 concrete slab specimens of dimensions 75 multiplied by 375 multiplied by 750 mm (3 multiplied by 15 multiplied by 30 in.), made with and without polypropylene fibers. Some specimens were cured under laboratory-controlled conditions and were subjected to the wet/dry cycles for 85 weeks, while others were cured under field conditions and were subjected to the same cycles for 50 weeks.

4034
Beaudoin, J. J.
"HANDBOOK OF FIBER-REINFORCED CONCRETE. PRINCIPLES, PROPERTIES, DEVELOPMENTS AND APPLICATIONS"
Noyes Publications, Park Ridge, NJ, 1990, xvii, 332 pp.

The state of the art of fiber-reinforced concrete systems is covered in this book. This book constitutes a contribution to the concrete literature during a period of dynamic growth of cement composite technology in the construction materials industry. The principles and modern theories predicting the role of fiber reinforcement in cement systems are introduced in a concise and logical manner. The latest developments and research on glass fiber-reinforced cement are presented in the context of behavioral mechanisms, matrix microstructure and fiber-matrix interface physics and chemistry. This methodology was also applied to cement composites containing polypropylene, polyethylene, polyamide, carbon, polyvinyl alcohol and numerous other fiber types.

4035
Chanvillard, G. and Aitcin, P-C.
"THIN BONDED OVERLAYS OF FIBER-REINFORCED CONCRETE AS A METHOD OF REHABILITATION OF CONCRETE ROADS"
Canadian Journal of Civil Engineering, Aug 1990, Vol. 17, No. 4, pp 521-527.

The progressive and rapid deterioration of cement concrete road systems makes frequent rehabilitation necessary if an acceptable level of service is to be maintained. When a road's structural capacity is still satisfactory, simple resurfacing to correct surface faults is an acceptable option. Several different types of resurfacing are possible, depending on adhesion developed at the interface. Dimensioning and selection of application techniques are still today purely empirical matters. However, major discoveries have been made about the behavior of overlays, especially regarding cracking. For example, reflection in the overlay of the cracks of the old pavement is inevitable with a bonded interface. The old cracks must, therefore, be repaired first. However, with steel fibre reinforced concrete, the knitting effect of the fibres will stabilize the cracks. Road-work performed along autoroute 40 in the suburbs of Montreal provided an opportunity to monitor the behavior of a thin bonded overlay of fibre-reinforced concrete. Examination of the road more than 2 years after it was recommissioned clearly indicated that the fibres had a positive effect on the condition of the road. In French.

4036
Leming, M. L., Ahmad, S. H., Zia, P., Schemmel, J. J., Elliott, R. P., and Naaman, A. E.
"HIGH PERFORMANCE CONCRETES. AN ANNOTATED BIBLIOGRAPHY. 1974-1989"
Strategic Highway Research Program, Wash. D. C., 1990, 403 pp. (SHRP-C/WP-90-001)

This bibliography is the result of an extensive literature search on the subject of high-performance concrete (defined as concrete with either a 3-hour strength of not less than 3,000 psi, a 24-hour strength not less than 5000 psi, a 28-day strength not less than 10,000 psi, or a water cement ratio less than 0.35; as well as have a durability factor not less than 80 after 300 cycles of freezing and thawing). The bibliography covers a period of 15 years beginning in 1974, and consists of two sections: (I) plain concrete and (II) fiber reinforced concrete. An author index and a subject index are included.

4037
Liang, R. Y. and Galvez, E.
"HIGH STRENGTH, HIGH DENIER DISCRETE POLYMER FIBER IN CEMENTITIOUS COMPOSITES"
in Serviceability and Durability of Construction Materials, Proceedings of the First Materials Engineering Congress, held Aug 13-15, 1990, Denver, CO; Ed. by Bruce A. Suprenant; ASCE, New York, 1990, Vol. 2, pp 894-902.

A series of 3-point beam tests were performed on the cementitious composites specimens reinforced with high strength, high denier discrete polyester fibers. The fiber length, fiber volume fraction, and cement matrix mixture were varied to study their effect on flexural behavior of composites. The peak-load capacity and toughness of beam specimens were shown to be improved with addition of fibers.

4038
Mobasher, B., Ouyang, C., and Shah, S. P.
"HIGH PERFORMANCE FIBER REINFORCED CEMENT-BASED COMPOSITES"
in Serviceability and Durability of Construction Materials, Proceedings of the First Materials Engineering Congress, held Aug 13-15, 1990, Denver, CO; Ed. by Bruce A. Suprenant; ASCE, New York, 1990, Vol. 2, pp 725-734.

Fracture of cement-based composites reinforced by the relative high fiber volume was studied. Crack propagation and damage distribution were examined by laser holographic interferometry. Based on fracture mechanism observed during experimental studies, a R-curve approach has been proposed to predict toughening of matrices due to fiber reinforcement. The theoretical predictions show a good agreement with the experimental results.

4039
Ramakrishnan, V., Balaguru, P., Kostaneski, L., and Johnston, D.
"FIELD PERFORMANCE OF FIBER REINFORCED CONCRETE HIGHWAY PAVEMENTS"
in Serviceability and Durability of Construction Materials, Proceedings of the First Materials Engineering Congress, held Aug 13-15, 1990, Denver, CO; Ed. by Bruce A. Suprenant; ASCE, New York, 1990, Vol. 2, pp 903-912.

This paper reports the evaluation of field performance of fiber reinforced concrete pavements. The concrete was designed for a compressive strength of about 40 MPa. Steel fibers with hooked ends were used at the rate of 39.2 Kg/m3. Trial mix was tested for compressive strength, flexural fatigue strength, impact strength and strength gain with time up to 28 days. Test samples were also made during construction. Cores were also taken for evaluating the inplace strengths of fiber reinforced concrete. The pavement was inspected periodically. This paper presents details in the areas of (1) comparison of laboratory mixture and the mixture used in the field, (2) comparative performance of control specimens and cores, and (3) pavement condition report based on the field performance of FRC and plain concrete. The experience indicates that FRC can be constructed with normal construction equipment and its performance is better than plain concrete specially in the area of crack resistance and fatigue strength.

4040
Wang, Y., Li, V. C., and Backer, S.
"TENSILE PROPERTIES OF SYNTHETIC FIBER REINFORCED MORTAR"
Cement & Concrete Composites, 1990, Vol. 12, No. 1, pp 29-40.

This paper reports on an experimental study of synthetic fiber reinforced mortar. The fibers used included aramid, high- strength high-modulus polyethylene, and polypropylene, and they were randomly mixed in the matrix at volume fractions below 3%. Tensile properties of the composites were measured by the direct tensile test under both monotonic and cyclic loading. Workability and the drying shrinkage of the composites are also reported.

4041
Wecharatana, M.
"BRITTLENESS INDEX OF CEMENTITIOUS COMPOSITES"
in Serviceability and Durability of Construction Materials, Proceedings of the First Materials Engineering Congress, held Aug 13-15, 1990, Denver, CO; Ed. by Bruce A. Suprenant; ASCE, New York, 1990, Vol. 2, pp 966-975.

Series of direct tension tests were conducted to observe the softening response of different types of cementitious composites, namely, mortar, plain concrete, high strength concrete, normal fibrous concrete, and high strength fibrous concrete. The types of fibers used are straight and hooked end steel fibers with volume fraction of 0.5, 1.0, 1.5, and 2.0%. The strength of the matrix varied from 24 MPa to 83 MPa. Two types of direct tension specimens, a dog bone and an end-tapered specimen, were developed for monitoring the post-peak response of brittle composites like concrete. All tests were done in an MTS testing machine under closed-loop strain control. The complete load-displacement curve, both ascending and descending branches, of each test was closely monitored and recorded. A simple generalized stress-displacement relationship is proposed. A single variable named 'brittleness index' is introduced and used to model the softening response of different types of cementitious composites. The predicted responses agree closely with the experimental results.

4042
Yin, W. S. and Hsu, T. C.
"UNI- AND BI-AXIAL COMPRESSIVE FATIGUE OF FIBER CONCRETE"
in Serviceability and Durability of Construction Materials, Proceedings of the First Materials Engineering Congress, held Aug 13-15, 1990, Denver, CO; Ed. by Bruce A. Suprenant; ASCE, New York, 1990, Vol. 2, pp 1172-1181.

Fatigue behavior of fiber reinforced concrete was studied under uniaxial and biaxial loadings. The S-N curves and the cyclic deformations of fiber concrete were compared to those of plain concrete. It was found that the S-N curve of fiber concrete is a straight line from 1 to 1 million cycles, rather than a curve which can be approximated by two straight lines as in plain concrete. The addition of fibers to concrete increases the fatigue life as well as the ductility, while the failure mode remains the same.