Gao Hongbo, Sun Hongna, Wang Zhaokun, Han Xiaoyan, Li Xinru
School of Civil Engineering and Architecture, Hainan University, Haikou 570228, China.
School of Hydraulic and Civil Engineering, Ludong University, Yantai 264025, China.
Materials (Basel). 2025 Apr 2;18(7):1616. doi: 10.3390/ma18071616.
To optimize the design of concrete beams and assess the performance of new materials, four-point bending tests were conducted to examine the bending behavior of alkali-activated concrete (ALAC) beams with different reinforcement ratios. The cracking load, displacement, and crack width were measured using the Digital Image Correlation (DIC) method and compared with results obtained through traditional methods. The findings demonstrate that DIC significantly outperforms traditional techniques in determining crack load, displacement, and crack width, particularly in capturing crack initiation and propagation. As the reinforcement ratio increases, the mid-span displacement at the peak load decreases for ALAC beams. At the same reinforcement ratio, the ALAC beam exhibits 1.07 times the bearing capacity, 1.4 times the mid-span displacement, and 0.72 times the maximum crack width compared to ordinary Portland cement concrete (PCC) beams. The cracking load, calculated using a plasticity coefficient of 1.17 for the section resistance moment, aligns closely with the experimental results. Furthermore, the formulas for mid-span displacement and maximum crack width in ordinary concrete beams can also predict the corresponding properties of ALAC beams. These findings validate the mechanical behavior and application potential of ALAC beams under various reinforcement ratios.
为了优化混凝土梁的设计并评估新材料的性能，进行了四点弯曲试验，以研究不同配筋率的碱激发混凝土（ALAC）梁的弯曲性能。使用数字图像相关（DIC）方法测量了开裂荷载、位移和裂缝宽度，并与传统方法获得的结果进行了比较。研究结果表明，在确定裂缝荷载、位移和裂缝宽度方面，DIC明显优于传统技术，尤其是在捕捉裂缝的萌生和扩展方面。随着配筋率的增加，ALAC梁在峰值荷载作用下的跨中位移减小。在相同配筋率下，与普通硅酸盐水泥混凝土（PCC）梁相比，ALAC梁的承载力是其1.07倍，跨中位移是其1.4倍，最大裂缝宽度是其0.72倍。使用截面抵抗矩塑性系数1.17计算的开裂荷载与试验结果吻合良好。此外，普通混凝土梁的跨中位移和最大裂缝宽度公式也可以预测ALAC梁的相应性能。这些发现验证了不同配筋率下ALAC梁的力学性能和应用潜力。
