ANALYSIS, COST ESTIMATION AND OPTIMIZATION OF REINFORCED CONCRETE SLAB STRENGTHENING BY STEEL AND CFRP STRIPS

As a result of the planned change of use, the imposed load on the existing reinforced concrete mezzanine slab will be significantly increased, wherefore a diagnostics and assessment of the current state of the structure has been carried out. The control calculation showed that the slab does not have sufficient bearing capacity for the increased load. After qualitative analysis of possible strengthening methods, two methods were selected for detailed analysis: strengthening with steel strips and strengthening with carbon fiber-reinforced polimer (CFRP) plates.

The criterion for choosing the optimal solution was the total cost of the material. It has been shown that the total price of materials for strengthening with steel strips is almost 40% lower than the price of strengthening with CFRP plates. It has also been observed that, when using steel strips, the contribution of the price of adhesive in the total cost of material is extremely high. When varying the level of strengthening, for imposed loads from 3 to 7.5 kN/m2, the ratio of the total costs of materials for steel and CFRP strips ranges between 60 and 73% and shows a slight tendency to increase with the increasment of loads.