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Water penetration into strain hardening cementitious composites before and after water-repellent surface impregnation
Published in Hiroshi Yokota, Dan M. Frangopol, Bridge Maintenance, Safety, Management, Life-Cycle Sustainability and Innovations, 2021
F. Wittmann, P. Zhang, T. Zhao
After compaction in steel forms, all specimens were allowed to harden in the concrete laboratory under wet burlap for 24 hours. Then the steel form was removed and the specimens were stored for 21 days in a moist curing room (20 °C, 95% RH). In this project, dumbbell shaped specimens with a thickness of 30 mm and an overall length of 330 mm were cast in steel forms. The width at both ends is 90 mm and the center part with a length of 120 mm has a width of 60 mm. In order to characterize mechanical properties of the SHCC under investigation, stress-strain diagrams have been determined. Typical results are shown in Figure 1. The average first cracking stress of this type of SHCC was approximately 2.1 MPa and the average ultimate tensile strain was approximately 3.8 %. The center part of the specimens, which was subsequently subjected to a uniform tensile stress, had the following size: 120×60×30mm. Finally, in order to determine capillary water absorption by means of neutron digital imaging, the center part has been cut out of the specimen after a predetermined tensile strain had been applied.
Foundations, Framing, Sheathing, and Vapor Barriers
Published in Kathleen Hess-Kosa, Building Materials, 2017
Asphalt-saturated felt, also referred to as asphalt-impregnated felt, asphalt felt paper, and felt paper, comprises pressure treated unwoven fibers impregnated with water resistant asphalt. Back in the 1800s, paper was coated with asphalt, but the tar-impregnated paper tore easily and rotted when it got wet. As a stand-alone product, asphalt impregnated paper, or cellulose fiber, was not reliable. Thus, the paper was replaced with more durable, but still susceptible to water damage, asphalt-impregnated heavy Kraft paper and organic rags (e.g., jute, burlap, etc.) which may still be found in houses dating back to the late 1800s. In 1910, asbestos came into common use as a component of roofing felt (U.S. EPA 1990). Then, in 1935, glass fiber was developed, later to be used as a sole component in the production of a completely inorganic asphalt felt which is still in use today—as a wall vapor retarder and as roofing underlayment. The cellulose felt paper is also used on flat roofs where hot asphalt is applied to the surface.
Overview of California studies on noise reduction for asphalt and concrete surfaces
Published in Andreas Loizos, Imad L. Al-Qadi, A. (Tom) Scarpas, Bearing Capacity of Roads, Railways and Airfields, 2017
J. Harvey, R. Wu, I. Guada, Q. Lu, A. Ongel, A. Rezaei, E. Kohler, C. Reyes
Concrete pavement surface texture types commonly used in California were included in the four year field study beginning in 2008: Diamond Ground (DG) and diamond grooved (Gr), which are used for pavement preservation and rehabilitation; and Longitudinally Tined (LT), which is used for new concrete pavements. Some results were also obtained for concrete pavement sections with Longitudinally Broomed (LB) and Burlap Drag (BD) surface textures. A limited number of test sections with the new Grind and Groove (GnG) texture were built late in the study and initial testing was performed on them.
Early Age Deflections in Newly Rehabilitated Steel Girder Bridges Made Composite with Concrete Slabs
Published in Structural Engineering International, 2019
Hema Jayaseelan, Bruce W. Russell, Alanna Corelle Webb
The ODOT specifies a curing regimen that requires wet curing for 10 days. Figure 9 shows that wet burlap was placed directly on the surface of the concrete. The burlap was subsequently covered with plastic sheeting. Curing was applied at 4.0 h after the beginning of casting. Prior to the application of burlap, the concrete deck surfaces were inspected for cracking and none were found. No early age cracking was reported. The deck was wet cured for 14 days after casting, and during that time the deck was covered by wet burlap on the top and by formwork on the bottom. Formwork on the underneath of the deck and on the sides of the deck remained in place during curing. Removal of formwork and bracing began after 11 days, but the wet burlap and plastic sheeting remained in place for 14 days. After removal of curing materials, the concrete deck was inspected for cracking. No cracks were found.
Field investigation of early-age behaviour of continuously reinforced concrete pavement with semi-rigid base
Published in International Journal of Pavement Engineering, 2022
Tao Bai, Zhijia Chai, Zheng Duan, Chunguang Mao, Zhenghong Huang, Wujun Zhou
The CRCP test section was located in Wuhan, constructed on August 15 2020. Figure 1 shows the schematic diagram of the CRCP structure. The 6 m wide CRCP section was composed of 24 cm concrete slab over 40 cm cement stabilised base. The resilient modulus of soil subgrade is designed to be greater than 110 MPa. The longitudinal steel ratio of CRCP is 0.73%. 1.8 cm diameter longitudinal steel bars were placed with 14.5 cm spacing at the 100 mm depth of the concrete slab. The concrete slab was cured with wet burlap sheets.
Evaluation of noisiness of exposed aggregate cement concrete pavement
Published in Road Materials and Pavement Design, 2021
Wladyslaw Gardziejczyk, Pawel Gierasimiuk, Marek Motylewicz, Marta Wasilewska
The sound spectra from traffic presented in Figure 7 show that in the frequency range 160–1600 Hz, the pavement texture (EACC11, MPD = 1.90 mm) have a significant impact on the sound level. Above 1250 Hz, higher sound levels were recorded on portland cement concrete textured using burlap drag. The reason for this is the very fine texture of the pavement and its effect on the increase in noise levels from passing multi-axle heavy vehicles.