Density, absorption and specific gravity tests of aggregates, bituminous mixtures and surfaces.

Mode of access: Internet.

Bibliography on resistance of bituminous materials to deterioration caused by physical and chemical changes, annotated.

Mode of access: Internet.

The Superpave mix design manual for new construction and overlays /

"Contract A-001"--T.p. verso.

Evaluation of the AASHTO design equations and recommended improvements /

"SHRP-P-394."

Bicycle/pedestrian trip generation workshop : summary /

"March 1998."

Public roads /

Title from cover.

Downtown versus suburban shopping.

Vol. 2 published by Ohio State University Research Foundation.

An Illinois pavement feedback system : feasibility and system requirements /

"Project IHR-517, Illinois Cooperative Highway Research Program."

Road and bridge construction specifications for AASHO road test project.

Research authority: National Academy of Sciences, Highway Research Board.

National experimental projects tabulation.

Mode of access: Internet.

Bibliography on frost action in soils; annotated.

Mode of access: Internet.

Proceedings of the ... annual meeting /

Report for 1922 includes a summarized account of preliminary and organization meetings in 1919,1920 and 1921.

Allocation of road and street costs.

pt. 1. An equitable solution to the problem. Sect. 1-5 by R. G. Hennes [et al.]--pt. 2. Classification, traffic volumes and annual costs of county roads and city streets in the state of Washington, by G. A. Riedesel.--pt. 3. Bases for weight-distance taxation in the state of Washington. v. 1. Automobiles & taxicabs. v. 2. Trucks & buses.--pt. 4. The benefits of rural roads to rural property, by Wm. L. Garrison.--pt. 5. The effect of freeway access uponsuburban real property values, by R. O. Wheeler.

Development of surface flaw thresholds for pre-cured fiber reinforced polymer and groove size tolerance for near surface mounted fiber reinforced polymer retrofit systems

Since the introduction of fiber reinforced polymers (FRP) for the repair and retrofit of concrete structures in the 1980’s, considerable research has been devoted to the feasibility of their application and predictive modeling of their performance. However, the effects of flaws present in the constitutive components and the practices in substrate preparation and treatment have not yet been thoroughly studied. This research aims at investigating the effect of surface preparation and treatment for the pre-cured FRP systems and the groove size tolerance for near surface mounted (NSM) FRP systems; and to set thresholds for guaranteed system performance. This study was conducted as part of the National Cooperative Highway Research Program (NCHRP) Project 10-59B to develop construction specifications and process control manual for repair and retrofit of concrete structures using bonded FRP systems. The research included both analytical and experimental components. The experimental program for the pre-cured FRP systems consisted of a total of twenty-four (24) reinforced concrete (RC) T-beams with various surface preparation parameters and surface flaws, including roughness, flatness, voids and cracks (cuts). For the NSM FRP systems, a total of twelve (12) additional RC T-beams were tested with different grooves sizes for FRP bars and strips. The analytical program included developing an elaborate nonlinear finite element model using the general purpose software ANSYS. The bond interface between FRP and concrete was modeled by a series of nonlinear springs. The model was validated against test data from the present study as well as those available from the literature. The model was subsequently used to extend the experimental range of parameters for surface flatness in pre-cured FRP systems and for groove size study in the NSM FRP systems. Test results, confirmed by further analyses, indicated that contrary to the general belief in the industry, the impact of surface roughness on the global performance of pre-cured FRP systems was negligible. The study also verified that threshold limits set for wet lay-up FRP systems can be extended to pre-cured systems. The study showed that larger surface voids and cracks (cuts) can adversely impact both the strength and ductility of pre-cured FRP systems. On the other hand, frequency (or spacing) of surface cracks (cuts) may only affect system ductility rather than its strength. Finally, within the range studied, groove size tolerance of ±1/8 in. does not appear to have an adverse effect on the performance of NSM FRP systems.

Development of thresholds for surface preparation in repair systems with wet lay -up fiber reinforced polymers

Bonded repair of concrete structures with fiber reinforced polymer (FRP) systems is increasingly being accepted as a cost-efficient and structurally viable method of rapid rehabilitation of concrete structures. However, the relationships between long-term performance attributes, service-life, and details of the installation process are not easy to quantify. Accordingly, there is currently a lack of generally accepted construction specifications, making it difficult for the field engineer to certify the adequacy of the construction process. ^ The objective of the present study, as part of the National Cooperative Highway Research Program (NCHRP) Project 10-59B, was to investigate the effect of surface preparation on the behavior of wet lay-up FRP repair systems and consequently develop rational thresholds that provide sufficient performance. ^ The research program was comprised of both experimental and analytical work for wet lay-up FRP applications. The experimental work included flexure testing of sixty-seven (67) reinforced concrete beams and bond testing of ten (10) reinforced concrete blocks. Four different parameters were studied: surface roughness, surface flatness, surface voids and bug holes, and surface cracks/cuts. The findings were analyzed from various aspects and compared with the data available in the literature. As part of the analytical work, finite element models of the flexural specimens with surface flaws were developed using ANSYS. The purpose of this part was to extend the parametric study on the effects of concrete surface flaws and verify the experimental results based on nonlinear finite element analysis. ^ Test results showed that surface roughness does not appear to have a significant influence on the overall performance of the wet lay-up FRP systems with or without adequate anchorage, and whether failure was by debonding or rupture of FRP. Both experimental and analytical results for surface flatness proved that peaks on concrete surface, in the range studied, do not have a significant effect on the performance of wet lay-up FRP systems. However, valleys of particular size could reduce the strength of wet lay-up FRP systems. Test results regarding surface voids and surface cracks/cuts revealed that previously suggested thresholds for these flaws appear to be conservative, as also confirmed by analytical study. ^