不同應力狀態下無機聚合物的破壞模式與力學特性研究

Failure Modes and Mechanical Characteristics of Geopolymers under Variying Confining Pressure

呂軒志(S. J. Lyu) ； 蕭宇翔(Y. H. Hsiao) ； 王泰典(T. T. Wang) ； 鄭大偉(T. W. Cheng) ； 翁祖炘(T. H. Ueng)

《鑛冶：中國鑛冶工程學會會刊》 56卷4期 (2012/12) Pp. 123-132

https://doi.org/10.30069/MM.201212.0014

摘要

本研究採不同SiO2/Na2O莫耳比製成無機聚合物進行一系列單軸壓縮與三軸壓縮試驗，探討不同應力狀態下無機聚合物的破壞模式與力學特性。研究結果顯示，無機聚合物於無圍壓縮條件下具有脆性材料之特徵，破壞呈劈裂形態；隨著圍壓增加，其破壞模式會自劈裂形態轉向單斜剪裂、共軛剪裂或鼓脹變形等形態，且破壞時臨界應變隨之增加。無機聚合物的視凝聚力隨SiO2/Na2O莫耳比增加而降低，而視摩擦角在相近的破壞模式下則隨SiO2/Na2O莫耳比增加而增加，但自剪裂破壞形態轉變至鼓脹變形過程存在明顯的減降。本研究探討的SiO2/Na2O莫耳比範圍內，莫耳比愈低，無機聚合物聚合程度愈佳，破壞模式與力學特性受到組成配比與應力狀態高度影響。

關鍵字

無機聚合物 ； SiO2/Na2O莫耳比 ； 破壞模式 ； 破壞包絡線 ； 應力-應變曲線

並列摘要

This research conducted uniaxial compression and triaxial compression tests on geopolymers under varying confining pressures. The geopolymers were prepared with compounds having various SiO2/Na2O mole ratios. The purpose was to investigate the associated failure modes and mechanical characteristics under different stresses. Experiment results showed that under the uniaxial compressive condition the geopolymer specimen failed in a splitting mode as a brittle material. As the confining pressure increased, failure mode changed to mono shear crack, conjugated shear crack, or bulge failure with an increasing failure strain. The apparent cohesion of geopolymer decreased when SiO2/Na2O mole ratio was increased. For geopolymer with similar failure mode, the apparent friction angle increased as the SiO2/Na2O mole ratio was increased. A significant reduction can be observed as the failure mode changed from shear to bulge. The apparent cohesion of geopolymer improved as the SiO2/Na2O ratio was decreased. The failure mode and geopolymer strength are highly affected by the mixture composition.

並列關鍵字

geopolymer ； SiO2/Na2O mole ratio ； failure mode ； failure envelope ； stress-strain curve