tailieunhanh - Test procedure for shrinkage of concrete blocks

In this paper, methods of testing the drying shrinkage of concrete blocks are evaluated. Tests were done on blocks of differing strengths, suppliers and curing procedures. The shrinkage tests were carried out as recommended in ASTM C426 [1], using the whole block as specimens and with gauge discs attached to the sides. Three variations of this set-up were also tested: a face-shell prism cut from a whole block with gauge plugs attached to the sides, the same specimen with gauge discs attached to the top and bottom and whole blocks with gauge discs attached to the top and bottom. For the case of gauge discs attached to the sides, a Humboldt strain gauge was used to measure deformation. In the case of gauge discs attached to the top and bottom, a comparator was used. Deformations on control blocks left inside the laboratory, and not submitted to the saturated and dry conditions of the ASTM C426 test, were also measured for nearly 90 days. | Canadian Masonry Symposium Banff Alberta June 8 - 12 2005 TEST PROCEDURE FOR SHRINKAGE OF CONCRETE BLOCKS G. A. Parsekian1 K. C. Barbosa2 T. B. Inforsato3 D. F. Deana4 M. S. Faria5 and C. O. da Silva6 1Professor Dept of Civil Engineering Federal University of Sao Carlos gparsekian@ 2MSc Dept of Civil Engineering Federal University of Sao Carlos klecbarbosa@ 3Graduate Student Dept of Civil Engineering Federal University of Sao Carlos thinforsato@ Junior Engineer Brazilian Portland Cement Association davidson@ 5Senior Engineer Brazilian Portland Cement Association laboratory Engineer Brazilian Portland Cement Association claudio@ ABSTRACT In this paper methods of testing the drying shrinkage of concrete blocks are evaluated. Tests were done on blocks of differing strengths suppliers and curing procedures. The shrinkage tests were carried out as recommended in ASTM C426 1 using the whole block as specimens and with gauge discs attached to the sides. Three variations of this set-up were also tested a face-shell prism cut from a whole block with gauge plugs attached to the sides the same specimen with gauge discs attached to the top and bottom and whole blocks with gauge discs attached to the top and bottom. For the case of gauge discs attached to the sides a Humboldt strain gauge was used to measure deformation. In the case of gauge discs attached to the top and bottom a comparator was used. Deformations on control blocks left inside the laboratory and not submitted to the saturated and dry conditions of the ASTM C426 test were also measured for nearly 90 days. The results of the concrete block shrinkage test were influenced very little by the different type of initial three-day cure althought different shrinkage values were observed in the control blocks for each cure type. With regard to the test procedures only small differences in results were obtained with whole blocks or face .

• Kiến trúc - Xây dựng
• Test procedure for shrinkage
• Shrinkage of concrete blocks
• Suppliers and curing procedures
• Gauge discs attached to the sides
• Measure deformation