건설재료시공학연구실

Building material & construction lab.

Abstract
The generally apartment houses in the 1980s are comprised of the topping concrete of the flat-roof. These topping concrete is requires advanced quality control of durability, because it directly is subjected to the deterioration factors of environments.

 However, the topping concrete is not correct a standard specification and a maintenance guidelines by reason of the nondearing structures. In addition, it is in bad keep the document for the mixing ratio site and thickness of the topping concrete. Therefore, the topping concrete is required standard valuation to decide whether is retention or not for repair works.
 As a result of actual state on the field, most topping concrete is occurred to deteriorate the surface crack, spalling, and pop-out scaling etc. Moreover, it is evaluated to the deterioration of general topping concrete through the freezing-melting, rebound test, neutralization, alkalinity, air void, and X-ray diffraction.
 These results lead us to the conclusion that the main cause of deteriorated topping concrete was decided that wouldn't be fulfilled quality control of concrete and was founded to accelerate deterioration of topping concrete for the neutralization and freezing-melting.