This paper examines a progression of experimental studies designed to investigate the response of reinforced concrete slabs subjected to static and high-mass low-velocity impact loads. A total of ten reinforced concrete slabs were tested: three specimens were tested under static load by loading the specimens at their mid-point, and seven specimens were tested under impact load to research the high-mass, low-velocity impact behaviours of reinforced concrete slabs using a dropweight facility. Measurements methods included a load cell, acceleration, strain in the reinforcement steel and a laser sensor to measure deflection in the centre and various quarters of the slabs (LVDT). The experimental variables included in this study focused mainly on the thickness of slab under static and impact loads, the mass of the striking object, and the height of the striking object for impact loads. The results showed that under static loads, the mean of the thickness of the slab increased by 33 to 100%, the maximum deflection at the central point decreased by 45 to 63 %, and the load capacity of the slabs increased by 77 to 265%. With respect to high-mass low-velocity impact loads, as the slab thickness increase by 33to 100%, the maximum deflection at the centre of the slabs decreased by 47.7 to 84 % and the impact force increased by 37.5 to 102%. When the height of the striking object was increased by 33 to 66%, the maximum central deflection of the slabs also increased by 24 to 72.3%, and the impact loads increased by 11 to 23.3%. Increases in the mass of the striking object by 50 to 100% led to the maximum central deflection of the slabs increasing by about 54 to 122% and to the impact loads increasing by 13 to 18.6%.

This paper shows a progression of experimental studies to investigate the response of reinforced concrete slabs when subjected to high-mass low-velocity impact loads. The researcher has confirmed that FRP composites are effective for strengthening a wide variety of concrete structural members. To date, very little published research has been performed on the behavior of strengthened two-way slabs under impact loads. The purpose of this study is to investigate experimentally on behavior slabs strengthening with CFRP. A total of seven reinforced concrete slabs were tested under the effect of impact load by a drop-weight facility. Measurements involved a load cell, accelerometer, strain gauges in the reinforcement steel and concrete, and using (a laser sensor, LVDT) to measure deflection in the center and quarter of the slabs. These experimental variables included in this study were focused mainly on the formation and dimension of carbon fiber under impact loads. The test results showed that the adding carbon fibers were active in increasing slab capacity and mitigating local damage under the impact, as the strengthening of slabs by CFRP, the increased in an impact force of the slabs about (11.9– 19.5%) and the maximum deflection at the central slabs decreased by (6.5–22%). It can be observed that the increase in the area of the CFRP layer under the impact region led to more decrease of the deflection. With regard to acceleration, it is evident that the distribution of forces acting on the plate also varies over the course of the event and that the evolution of the inertial force resulted in load distributions that are significantly different from those developed in static test conditions. The evolution of inertial forces in impact loading conditions resulted in observed responses then failure patterns governed by shear. 

Numerical models for impact load assessment are becoming increasingly reliable and accurate in recent years. The processing time duration for such analysis has been decreased to an acceptable level when combined with modern computer hardware. The aim of this study was to represent a simulation technique and to verify the validity of modern software in measuring the response of reinforced concrete beam strengthened by carbon fiber-reinforced polymer (CFRP) sheet subjected to impact loads at the ultimate load ranges. In this investigation, ABAQUS/Explicit Software’s nonlinear finite element modeling had been used. The response of the impact force–time history and the displacement–time history graphs were compared to the existing experimental results. The adopted general-purpose finite element analysis is verified to be capable of simulating and accurately forecasting the impact behavior for structural systems. In addition, a parametric analysis was carried out to gain a better knowledge of the performance of reinforced concrete beams under impact loading. Four parameters had been changed among the analyzed beams such as impact velocity, impact mass, CFRP sheet thickness, and compressive strength of concrete. Generally, it has been found that using a CFRP sheet in strengthening reinforced concrete beams can greatly improve the members’ impact behavior by improving stiffness as well as increasing load-carrying capacities. The enhanced performance characteristics of strengthening beams under impact loads correlate with the applied kinetic energy and CFRP thicknesses. Finally, for beams with high compressive strength, the deflection values were reduced because of the increase in stiffness.