A report that explains testing of standard mix designs to determine minimum-required performance levels for developing performance-based concrete mix design criteria.
The reuse potential of tire chips as coarse aggregates in pavement concrete was examined in this research by investigating the effects of low- and high-volume tire chips on fresh and hardened concrete properties. One concrete control mixture was designed, which well exceeds CDOT Class P concrete requirements.
The purpose of this study was to determine the effectiveness of Class N fly ash and other pozzolans for mitigating alkali-silica reaction (ASR) and resisting sulfate attack.
This report presents a case study on the evaluation of bridge decks using various non-destructive test methods. The primary interest lies in quantifying delaminated areas in deck concrete covered with asphalt overlays. Analytical and computational models are formulated to decompose the intensity of GPR scales into two categories: i) initiation and progression of corrosion and ii) delamination of deck concrete, which show good agreement with repaired areas. Parametric investigations emphasize the significance of rebar spacing and concrete cover in determining the extent of deck delamination.
This report presents the development of ultra-high performance concrete (UHPC) using locally available materials that reduce construction costs compared with commercial products. With the aim of achieving a specified compressive strength of 20 ksi, a UHPC mixture is formulated. The implications of various constituent types are examined with an emphasis on silica compounds (silica fume, silica powder, silica sand, finer silica sand, pyrogenic silica, and precipitated silica), including steel and polypropylene fibers. Bond tests are conducted to evaluate the development length of the UHPC. Cost analysis shows that the prototype UHPC is up to 74% less expensive than commercial products.
This report covers the pre-construction, construction and the first evaluation following construction at the following locations: I-25, Colorado Boulevard; I-25, Pueblo; Highway 85, Santa Fe Avenue; and I-70, Flagler. An additional project has been added that will be constructed during the 1992 construction season. This project is located on Brighton Boulevard between I-70 and Sand Creek. This project will contain a section with Type I polymer, a section with Type III polymer and also a section with no binder.
The purpose of the report is to identify differences in Colorado's aggregates and asphalt cements as measured and compared to some of the European tests and specifications. Performance-related tests for asphalt cements developed by SHRP will be the ultimate method to identify performance and should be well received in Europe. Based upon the standard empirical tests on asphalt cements from four refineries commonly used in Colorado, the asphalt cements are comparable to those used in France. The 17 most frequently used aggregate sources in Colorado were tested for the study. The angularity of fine aggregates is measured with the NAA test procedure. The quality of the P200 is measured with respect to angularity, durability, and stiffening.
