FIGURE 1 Particle size grading curve

2.2 Concrete Block

In this experiment, the mortar cubes were prepared with a ratio of cement, sand, and water of 1:3:0.65 (by weight). Due to the relatively small size of the samples, larger particles in the sand were removed to ensure the uniformity of the mortar cube samples. During the sample preparation process, Vaseline was first applied around the iron mold (with a height of 25 mm). The concrete mortar was then evenly poured into the mold, and vibrated and smoothed to ensure that the thickness of the concrete sample was the same as the height of the mold. Subsequently, a standard curing procedure was followed, involving natural curing through watering every 8 hours at a temperature of 25°C to achieve hydration. After 28 days of curing, the mold was removed. Finally, samples with a height of 25 mm and uniform surface roughness were selected for further measurements as the final mortar cube samples. The process of preparing the mortar cubes is shown in Figure 2.