UHPC-ALC复合墙体材料优化及结构力学性能

Optimization of UHPC-ALC Composite Wall Materials and Structural Mechanical Properties

摘要:

为制备超高性能混凝土（UHPC）与蒸压轻质混凝土（ALC）复合墙体材料（UHPC-ALC），通过优化UHPC配合比并制备以ALC为芯层、UHPC为面层的复合墙体，研究了不同厚度UHPC面层和ALC芯层复合墙体材料的力学性能和热工性能。结果表明：硅灰15%、粉煤灰微珠10%、钢纤维2.0%（体积掺量）、胶砂比1.2时，UHPC的性能最优；当ALC含水率为50%且采用苯丙乳液界面剂时，UHPC-ALC的界面黏结性最佳；当UHPC面层厚度为5、10、15 mm时，较ALC试件，UHPC-ALC试件抗压强度分别提升20.8%、81.8%、111.3%，抗弯强度分别增长206%、281%、325%，破坏模式由脆性转为延性；当ALC芯层厚度不小于100 mm时，UHPC-ALC可满足中国严寒C区至夏热冬暖地区隔墙的热工要求；ALC芯层厚度不小于150 mm时，UHPC-ALC可满足中国各地区外墙的热工标准要求。

Abstract:

An ultra-high performance concrete（UHPC） and autoclaved lightweight concrete（ALC） composite wall material （UHPC-ALC） was prepared by optimizing the UHPC mix proportion and fabricating a composite wall with an ALC core layer and UHPC face layers. The mechanical and thermal properties of composite walls with varying thicknesses of UHPC face layers and ALC core layers were investigated. The results indicate that optimal UHPC performance is achieved with 15% silica fume， 10% fly ash beads， 2.0% steel fiber （by volume）， and a binder-to-sand ratio of 1.2； optimal interfacial bonding between UHPC and ALC is obtained when ALC has a moisture content of 50% and a styrene-acrylic emulsion interface agent is applied. With UHPC face layer thicknesses of 5， 10， and 15 mm， the compressive strength of UHPC-ALC specimens is increased by 20.8%， 81.8%， and 111.3%， respectively， compared to ALC specimens， while the flexural strength is increased by 206%， 281%， and 325%， respectively， with the failure mode transitioning from brittle to ductile. When the ALC core layer thickness is not less than 100 mm， UHPC-ALC satisfies the thermal insulation requirements for interior walls in regions ranging from China’s severe cold zone C to hot summer and warm winter zones； when the ALC core layer thickness is not less than 150 mm， UHPC-ALC meets the thermal insulation standards for exterior walls across all climatic regions in China.