P. Robins et al., Flexural strain and crack width measurement of steel-fibre-reinforced concrete by optical grid and electrical gauge methods, CEM CONCR R, 31(5), 2001, pp. 719-729
A research programme is discussed, which has investigated the fracture of s
teel-fibre-reinforced sprayed concrete under flexural loading, with the aim
of developing a stress-block model to predict flexural behaviour in the fo
rm of a load-deflection response. This paper reports the work associated wi
th establishing the strain and crack width profiles in relation to mid-span
beam deflection. A strain analysis technique is described, which combines
the use of electrical strain gauges with a semiautomated grid method (using
digital image processing) for measuring and monitoring the strain and crac
k width profile over the depth of a fibre-reinforced beam during a flexural
test. This novel strain analysis technique has established strain/crack wi
dth data, which forms a key part of a stress-block approach for predicting
residual flexural strength, an essential requirement of a much needed desig
n rationale for steel-fibre-reinforced concrete. (C) 2001 Elsevier Science
Ltd. All rights reserved.