This research study used metakaolin as a raw material, a mixed solution of sodium hydroxide and sodium silicate as an alkali excitant, and a graphene dispersant as an additive to manufacture a graphene geopolymer sample. The compressive strength and bending strength of the sample were tested. The results showed that the geopolymer hydration products were observed to be more compact, and the internal porosity was reduced after the addition of the graphene. The geopolymer strengths had been obviously increased, and the compressive strength and bending strength reached 46.9MPa and 6.7MPa, respectively. However, the graphene’s role in improving the strength of the original geopolymer became gradually weakened when the addition amounts of the graphene were increased to a certain extent. Furthermore, the role of the graphene in improving the compressive strength of the geopolymer was determined to gradually decrease with the increase in the content of sodium hydroxide in the alkali excitant.

Experimental studies on fatigue behavior of reinforced concrete slab with stainless steel rebar and carbon steel rebar have shown that, at the same reinforcement ratio, the slope of the deflection‐cycle number curves of stainless steel‐reinforced concrete slab is lower than that of ordinary steel‐reinforced concrete slab. The higher the reinforcement ratio is, the smaller the maximum crack width would be. Higher stress level contributes to larger deflection and reinforcement strain in midspan and shorter fatigue life. Compared to the ordinary steel‐reinforced concrete slab, the stainless steel‐reinforced concrete slab shows narrower maximum crack under the same number of loading cycles. Less significant midspan deflection, reinforcement strain, and longer fatigue life are observed in stainless steel‐reinforced concrete slab at the same reinforcement ratio, stress level, and cycling time. With the increase of reinforcement ratio, the deflection and fatigue life extended.

In this research study, the characteristics of ship–bridge collision force formulas, in Chinese standards as well as international standards, were analyzed. By considering the damage situations of bridge piers under the cumulative ship collision conditions, a method of combining theoretical deduction with numerical analysis was adopted in this study. The goals of this study were to analyze and examine the sizes of the ship–bridge collision forces, along with the damage situations of piers, in order to propose a collision force calculation formula which took cumulative pier damages into consideration. Also, experimental verifications and an applicability analysis of the proposed formula were performed.

In this study, stainless steel bars with the same diameter were used to replace ordinary stressed steel bars in reinforced concrete bridge piers. An ultra-high drop hammer impact test system was adopted for multiple horizontal impact tests on two groups of reinforced concrete bridge pier specimens. Based on the study results, it was determined that the maximum impact force of the stainless steel–reinforced concrete specimen, strain occurred in the steel bar and concrete, and the maximum displacement at the specimen’s top was found to be smaller than that before the same diameter replacement under the same impact energy. These results indicate that the stainless steel–reinforced concrete bridge pier specimen may have strong ductility, energy absorption abilities, and impact resistance under the impact load.

The reinforced concrete structure of a port wharf is affected by steel corrosion and ship docking impact. Replacing an ordinary steel bar with a stainless steel bar can solve the corrosion problem of the steel bar while ensuring the bearing capacity of the structure. However, the research on impact resistance of stainless steel-reinforced concrete structure is not perfect. In this paper, impact mechanical properties of reinforced concrete beams before and after equal strength replacement of stainless steel bars are analyzed by theoretical analysis and drop hammer impact test, and the possibility and applicable scope of equal strength replacement of stainless steel bars are put forward. The results indicated the following: (1) when the reinforcement ratios were small (0.21% to 1.32%), the stainless steel-reinforced concrete beams with equal strength were able to effectively reduce the stiffness losses of the beams undergoing impact loads, as well as improve the elastic resilience abilities, and reduce the structural damages. Therefore, the corrosion and impact problems of reinforcements could be solved by replacing ordinary reinforcements with stainless steel reinforcements and (2) when the reinforcement ratios were large (1.32% to 2.57%), the shear failures of the stainless steel-reinforced concrete beams were observed to be relatively serious, and the impact resistance performances had worsened. The research results provide technical support for the engineering application of stainless steel-reinforced concrete structure design.

In this experimental study, for the purpose of furthering the understanding of the effects of different reinforcement ratios on the impact resistance behaviors of reinforced concrete (RC) beams, a series of vertical impact tests were conducted on five RC beams with different reinforcement ratios using a domestically advanced ultrahigh heavy drop hammer impact testing machine system. The impact velocities and force of the drop hammer during the impacts, displacements, and strain of the test points, as well as the crack propagation process, were collected and analyzed. The experimental test results revealed the following. (1) When the reinforcement ratios ranged between 0.58 and 1.63 %, the RC beams had mainly suffered bending failures. However, when the reinforcement ratios were increased, it was observed that the overall stiffness of the beams had been effectively improved; displacements, steel strain, and damages were reduced; and the impact resistance abilities of the beams had been enhanced. (2) When the reinforcement ratios had ranged from 1.63 to 2.57 %, shear failures were found to be the main failure mode of the RC beams. It was found that increases in the reinforcement ratios could not effectively reduce the damages and were not conducive to the beams’ resistance to impact loads. (3) It was determined that because of the shearing effects of the impact loads, the shear force of the RC beams had increased.