Strengthening of Concrete Structures Using UHPC - Experimental Verification

Abstract

UHPC is a material which exhibits excellent mechanical properties and durability. Beside new structures it is also convenient for strengthening of existing structures. The paper investigates the possibilities of strengthening experimentally. A part of the experimental program is presented which is focused on bond of UHPC and existing concrete and on behaviour in bending. Acceptable bond may be achieved when the existing concrete is clean and reasonably rough. Structural elements are exposed to positive and negative bending moments. If UHPC overlay is applied, it works in compression and in tension. The experiments were therefore focused on verification of both alternatives (UHPC in compression and in tension). Finally, the conclusions from the experiments are drawn, which may be applied in practical design.

Strengthening of Concrete Structures Using UHPC

“…The individual experiments showed the efficiency of strengthening under different modes of loading. The performance in bending was described in earlier papers [1], [2], [3]. The efficiency of the strengthening in punching and of the strengthening of columns is briefly mentioned in this paper.…”

“…The slabs are most often horizontal, which makes it possible to use a self-compacting UHPC with usual composition and fibre contents. The fibre contents used in laboratory tests [1]- [3], which exhibited reasonable results, was about 2%. The continuous slabs (the most frequent case) are exposed to positive and negative bending moments.…”

“…1 and 2. Similarly as in the bending tests [1], [2], [3], the reinforced concrete slabs were strengthened by the UHPC layer cast on the top surface of the slab. Two alternatives of strengthening were investigated.…”

“…UHPC layer added to the surface of an existing structure can provide a very powerful tool increasing the load carrying capacity of a structural element. The paper applies the knowledge gained from an extensive experimental program [1], [2], [3] and provides a basic information on application of UHPC for strengthening of concrete structures.…”