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yes / Shear failure of concrete elements reinforced with Fiber Reinforced Polymer (FRP) bars is generally brittle, requiring accurate predictions to avoid it. In the last decade, a variety of artificial intelligence based approaches have been successfully applied to predict the shear capacity of FRP Reinforced Concrete (FRP-RC). In this paper, a new approach, namely, biogeography-based programming (BBP) is introduced for predicting the shear capacity of FRP-RC beams based on test results available in the literature. The performance of the BBP model is compared with several shear design equations, two previously developed artificial intelligence models and experimental results. It was found that the proposed model provides the most accurate results in calculating the shear capacity of FRP-RC beams among the considered shear capacity models. The proposed BBP model can also correctly predict the trend of different influencing variables on the shear capacity of FRP-RC beams.

In this thesis an evaluation is made of the results of approximately 1200 designs for one-way and two-way slabs meeting the requ1rements of the A.C.I. Code (1). The parameters have been chosen to cover a wide range of practical design conditions. The data resulting from these designs have been plotted using dimensionless parameters evaluated from a dimensional analysis approach. Curves fitting the data proved to be continuous over the working range, so equations for the curves were developed. Data from the original designs were compared with results computed from the developed equations. In a few cases maximum deviations of less than three percent were found. The average deviation for all designs was found to be less than one percent. / Master of Science

An experimental investigation was conducted to develop a laboratory technique for the nondestructive evaluation of reinforced concrete. The methodologies were developed with the intent of eventual field implementation to determine the feasibility of utilizing infrared thermography to inspect substructural elements of concrete bridges. Several specimen configurations were fabricated for thermographic inspection. A number of tests were performed on a variety of concrete specimens to determine the implementation parameters of the technique. The necessity of utilizing artificial heating methods for thermal input prior to inspection was evaluated. The present study suggests that infrared thermography cannot be applied to substructural elements of bridges in a noncontact fashion. Internal thermal gradients produced by diurnal temperature fluctuation generally are not sufficient to produce the variations in surface temperature patterns necessary for thermographically detecting nonvisual subsurface defects. Rather, both the envelopment and artificial heating of the substructural element is required prior to thermographic inspection. / Master of Science

yes / ACI Committee 544’s repeated drop-weight impact test for concrete is often criticized for large variations within the results. This paper identifies the sources of these large variations and accordingly suggests modifications to the ACI test. The proposed modifications were evaluated and compared to the current ACI test by conducting impact resistance tests on 40 specimens from two batches of polypropylene fiber-reinforced concrete (PPFRC). The results obtained from both methods were statistically analyzed and compared. The variations in the results were investigated within the same batch and between different batches of concrete. The impact resistance of PPFRC specimens tested with the current ACI test exhibited large coefficients of variation (COV) of 58.6% and 50.2% for the first-crack and the ultimate impact resistance, respectively. The corresponding COV for PPFRC specimens tested according to the modified technique were 39.4% and 35.2%, indicating that the reliability of the results was significantly improved. It has been shown that, using the current ACI test, the minimum number of replications needed per each concrete mixture to obtain an error below 10% was 41 compared to 20 specimens for the modified test. Although such a large number of specimens is not good enough for practical and economical reasons, the reduction presents a good step on the development of a standard impact test.

Reinforced concrete structures were originally designed on the elastic behavior of the materials by the "Working Stress Design Theory". As reinforced concrete structures became more widely used, another theory based on the inelastic behavior of materials was developed and is commonly known as the “Ultimate Strength Design Theory.” Recently, the attention has been focused on another design theory known as “Limit Design Theory.” This theory is based on the redistribution of moments at high loads. This thesis presents the comparison of these three theories of reinforced concrete. The members of an interior panel of a continuous framed structure are designed by the working stress design method and then a few members are analyzed by the above three design methods. The comparison has been made on the basis of the live load as a common denominator. The results of the analyses show that the overall increase in live load is 13 percent by ultimate strength analysis and 52 percent by limit design analysis. This further shows that limit design is a more efficient method for statically indeterminate structures. / Master of Science

Deterioration of reinforced concrete bridge decks has gained widespread public attention and concern in recent years. Much of the damage can be attributed to corrosion of steel reinforcing bars. Numerous solutions have been suggested, one of which is the replacement of steel with a non-corroding reinforcement, such as fiberglass-reinforced plastic materials. Much of the current research focuses on the applicability of FRP as the main tensile reinforcement in the slab. The nature of FRP presents many obstacles to its use in this capacity. This investigation aims to capitalize on the strengths of both steel and FRP by combining them. Traditional steel rebar should be used where it will provide strength and ductility to the deck --in the bottom layer of reinforcement. The FRP is placed where it will provide strength and non-corroding reinforcement where it is needed: the top layer. Recent research has shown that minimal negative moment is created over supports in bridge decks, suggesting that the use of the non-ductile FRP as the top reinforcement would not be detrimental. A review of prior and current research in this area was conducted. Based on this information, four different FRP reinforcing materials were obtained. Simple-beam test specimens were designed and built. The procedure is described, and experimental results are presented and analyzed. Conclusions are drawn and recommendations for future work are outlined. This investigation provides first-hand data on the behavior ofFRP reinforced concrete and will serve as the basis for future work. / Master of Science

This study investigates the effects of typical construction details on the strength of steel deck reinforced concrete composite slabs. Past research on composite slabs has been centered primarily around single span, single panel width slabs with unrestrained ends. The test specimens in this study are more representative of actual slab construction. The effects of multiple spans, multiple panels, end restraint from pour stops, and deck anchorage from shear studs and welds are investigated. The results of this experimental study are analyzed using methods given in the Steel Deck Institute Composite Deck Design Handbook. The models were found to conservatively predict the strength of the composite slabs. Recommended modifications to the calculation methods are given. / Master of Science