Fiber Reinforced Concrete Testing for Practical Application

One of the possible factors inhibiting the wider application of fiber concretes is the fact that to characterize the engineering properties of fiber concrete, both cubes/cylinders and prisms have to be cast and tested, in addition to the determination of workability. This paper demonstrates that by using superplasticizer, the slump test can be used to give guidance on the flowability characteristics of the fresh fiber concrete. The advantage of the slump test is that it is easy to perform in the field, apart from its simplicity and convenience. It is further shown that the equivalent cube strength obtained from the broken pieces of a flexural test can adequately represent the compressive strength of fiber concretes. It is thus shown that it is possible to characterize the engineering properties of fiber concretes from only one set of prisms, say, of 100x100x500 mm size. Apart from first crack load, modulus of rupture, and fracture toughness properties, the prisms can be employed to give additional information as appropriate, such as shrinkage and expansion, and through pulse velocity, internal microcracking. It is suggested that by rationalizing this testing approach, it is possible to reduce not only the cost and inconvenience associated with different sizes of test specimens but also to enhance the relevance of some of the information obtained from such testing.