断裂能是评价玻璃纤维增加水泥（GRC）抵抗开裂能力的重要技术指标。本文通过试验研究玻璃纤维长度和用量、水胶比、砂胶比对预混浇注生产的GRC断裂能的影响。研究表明：玻璃纤维显著提高了水泥基材料的断裂能，玻璃纤维掺量不超过固体组分质量的3%时，GRC断裂能随着玻璃纤维掺量的增加而大幅增加，近似成直线关系。玻璃纤维掺量相同的情况下，随着玻璃纤维长度的增加，GRC的断裂能先增大后降低，玻璃纤维的长度为20mm时，GRC有较高的断裂能。GRC的断裂能主要来源于玻璃纤维的拔出能，水胶比和砂胶比都对玻璃纤维的拔出能有显著影响。水胶比的增加会降低GRC抗弯强度，但GRC的断裂能随着水胶比的增加大幅增加。水胶比从0.32增加至0.50时，GRC的断裂能增幅达227%。GRC的断裂能随着砂胶比的增加而下降。

Fracture energy is an important technical specification to evaluate the anti-cracking capacity of glass fiber reinforced cement (GRC). The effects of glassfibre length and content, water-to-binder ratio and sand-to-binder ratio on the fracture energy of GRC produced by premixed casting were studied through experiments. The results show that glassfibre significantly improves the fracture energy of cement-based materials. When the glassfibre content does not exceed 3% of the solid component mass, the fracture energy of GRC increases greatly with the increase of glassfibre content, which is approximately linear. When the glassfibre content is constant, the fracture energy of GRC increases first and then decreases with the increase of glassfibre length. When the glassfibre length is 20mm, GRC has higher fracture energy. The fracture energy of GRC is mainly derived from the extraction energy of glassfibre. Both the water-to-binder ratio and the sand-to-binder ratio have a significant effect on the extraction energy of glassfibre. The increase of water-to-binder ratio will reduce the flexural strength of GRC, but the fracture energy of the GRC increases significantly with increasing water-to-binder ratio. The water-to-binder ratio increased from 0.32 to 0.50, and the fracture energy of GRC increased by 227%. The fracture energy of GRC decreases with the increase of sand-to-binder ratio.