doi:10.3850/978-981-08-7920-4_S2-S74-cd

ABSTRACT

The long-term performance of partially pre-stressed concrete slabs is not known well. This type of structure permits tensile stress and even cracking in concrete members. As well as the cracking by loads, the additional cracking by the shrinkage of concrete complicates the problem still more. Short- and long-term loading tests of partially pre-stressed concrete slabs were conducted. Experimental results showed that due to the effect of shrinkage of concrete the static and dynamic rigidities of the partially pre-stressed concrete slabs decreased to 70% and 80% of the initial rigidities, respectively. Partial pre-stress was effective for the short- and long-term performance of the concrete slabs, by reducing the cracks and rigidity fall. The small amount of the normal stress due to pre-stress acted effectively during the long-termloading test. It is necessary to know the rigidity decrement of concrete slabs under the effect of pre-stress for estimating the long-term deflections and change in natural frequencies.

Keywords: Partial pre-stress, Concrete slab, Long-term deflection, Cracking, Creep, Shrinkage.

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