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70 CHAPTER 8 CONCLUSIONS The objective of this research was to develop engineering were then developed in terms of asperity depth, width, and design guidelines for aesthetic surface treatments of concrete angle of inclination based on the combined set of simulation barriers for safety shape profiles, such as the New Jersey or outcomes. F-shape barrier profile. The design guidelines were devel- Based on these preliminary guidelines, a crash test plan oped through extensive use of finite element simulation, in was developed in which the outcome of one test determined conjunction with full-scale vehicle crash testing. the configuration evaluated in a subsequent test. In other words, The New Jersey barrier was used for the development of the test matrix was adjusted as the crash tests were performed, the preliminary and the final design guidelines. Vehicular and the results were analyzed in order to maximize the impacts with the F-shape barriers are known to result in information available for adjusting and finalizing the rela- lower vehicle instabilities when compared with the New Jer- tionships for asperity depth, width, and angle. A full-scale sey barriers. The guidelines developed are, therefore, con- crash-testing phase was conducted. The OCD measurements sidered to be applicable to both New Jersey and F-shape con- from the tests enabled the adjustment of the thresholds for crete barriers. acceptable and unacceptable floorboard internal energy upon To develop design guidelines for the application of aesthetic which the final design guidelines are based. For review, the surface treatments on concrete safety shape barriers, a set of guidelines for safety shape concrete barrier aesthetic surface preliminary guidelines were initially developed. A parametric treatments are presented again in Figure 84 (see Figure 85 for study was performed using finite element simulations to estab- English units). lish these preliminary guidelines. Generalized types of surface For the convenience of use, guidelines developed for safety asperities were defined in terms of various parameters such as shape barriers in this research and the guidelines previously the width, depth, and angle of inclination. Parametric finite ele- developed by the FHWA and Caltrans for stone masonry ment simulations were performed for asperity angles of 30, guardwalls and for single-slope and vertical-face concrete 45, and 90 degrees, and each simulation was assigned an out- barriers, respectively, have been consolidated into a single, come of "acceptable," "marginal/unknown," or "unaccept- standalone set of guidelines that appears in the appendix. able" based on comparison of the internal floorboard energy The appendix provides adequate guidelines to assist the with the established threshold values. Preliminary guidelines designer with all current types of concrete barriers.