| 摘要 |
<p>1391687 Concrete flexural strength BATTELLE DEVELOPMENT CORP 16 June 1972 [6 July 1971 7 June 1972] 28351/72 Heading C1H A mix of concrete and fibres of a material having an elasticity modulus of at least 20 x 10<SP>6</SP> p.s.i., which fibres are substantially uniformly distributed in the mix with an average spacing between the axes of the fibres of up to 0À3 inch, which mix has at least a preselected flexural strength, is prepared by measuring the flexural strengths for a plurality of substantially different average effective bond areas of the fibres per unit area in planes normal to tensile strength in test specimens of the mix, plotting the measured flexural strengths as a linear function in rectangular coordinates of their respective average effective bond areas with the plotted line being extended to intercept the ordinate of a preselected flexural strength and reading at the intercept the corresponding average effective bond area, and providing and distributing the fibres in such quantity in the bulk mix that the average effective bond area of the fibres intersecting planes normal to the stress at known regions of highest tensile stress is at least the average effective bond area read at the intercept. Details of cross-sectional area, length and shape of fibres (e.g. steel wires) are given.</p> |
