西安建筑科技大学学报(自然科学版)

为降低泡沫轻质土工程费用、提高其工程应用性,分别采用0%、25%、33%、40%粉质黏土替代水泥制备泡沫轻质土,开展了不同土掺量泡沫轻质土的无侧限抗压强度试验与劈裂抗拉强度试验,评价了不同土掺量泡沫轻质土的干湿循环耐久性.结果表明:泡沫轻质土的强度随土掺量的增加而降低,当土掺量由0%提高至40%时,28 d抗压强度和劈裂抗拉强度的变化范围分别为2.88～1.02 MPa和0.57～0.2 MPa,且两者具有很好的线性关系.随着土掺量增大,泡沫轻质土的抗干湿循环能力不断下降,干湿循环后,40%土掺量的泡沫轻质土软化系数为0.75,强度由1.02 MPa降低至0.78 MPa.基于现有设计规范要求,提出泡沫轻质土作为路床区填料建议土掺量应小于33%,作为路堤区填料建议土掺量为33%～40%.

In order to reduce the engineering cost of foam lightweight soil and improve its engineering applicability, this paper used the silty clay to replace zero, 25%, 33% and 40% cement to prepare foamed lightweight soil(FLS), respectively. The unconfined compressive strength tests and splitting tensile strength tests of FLS were carried out with different soil contents. The dry and wet durability of FLS with different soil contents was evaluated based on the water absorption tests, drying tests and wetting-drying cycle tests. Results showed that the strength of FLS decreased with the increase of soil contents. When the soil contents increased from zero% to 40%, the compressive strength and splitting tensile strength of FLS cured after 28 days decreased from 2.88 MPa to 1.02 MPa and 0.57 MPa to 0.2 MPa, respectively, which presented good linear relationship. With the increase of soil contents, the FLS was much easier to degrade under wetting-drying cycle. When the soil content increased to 40%, the softening coefficient of FLS reduced to 0.75, and the strength decreased from 1.02MPa to 0.78MPa after wetting-drying cycle. It is suggested that the amount of soil contents in FLS should be less than 33% as roadbed filling and 33%～40% as embankment filling.

引言
1 试验用原材料与配合比
2 力学性能
3 耐久性试验
4 结论

表1 试验土样物理性质<br/>Tab.1 Physical properties of test soil sample

表1 试验土样物理性质
Tab.1 Physical properties of test soil sample

图1 试验土样颗分曲线<br/>Fig.1 Particle size distribution curve of test soil sample

图1 试验土样颗分曲线
Fig.1 Particle size distribution curve of test soil sample

表2 水泥化学成分<br/>Tab.2 Chemical composition of cement

表2 水泥化学成分
Tab.2 Chemical composition of cement

表3 泡沫轻质土配合比设计<br/>Tab.3 Mix design of foamed lightweight soil

表3 泡沫轻质土配合比设计
Tab.3 Mix design of foamed lightweight soil

图2 不同素土掺量的泡沫轻质土试件<br/>Fig.2 Foamed lightweight soil samples with different soil contents

图2 不同素土掺量的泡沫轻质土试件
Fig.2 Foamed lightweight soil samples with different soil contents

图3 不同土掺量泡沫轻质土无侧限抗压强度<br/>Fig.3 Unconfined compressive strength of foamed lightweight soil with different soil contents

图3 不同土掺量泡沫轻质土无侧限抗压强度
Fig.3 Unconfined compressive strength of foamed lightweight soil with different soil contents

图4 不同土掺量泡沫轻质土劈裂抗拉强度<br/>Fig.4 Splitting tensile strength of lightweight foamed soil with different soil contents

图4 不同土掺量泡沫轻质土劈裂抗拉强度
Fig.4 Splitting tensile strength of lightweight foamed soil with different soil contents

图5 劈裂抗拉强度与无侧限抗压强度关系<br/>Fig.5 Relationship between splitting compressive strength and unconfined compressive strength

图5 劈裂抗拉强度与无侧限抗压强度关系
Fig.5 Relationship between splitting compressive strength and unconfined compressive strength

图6 不同饱水状态下泡沫轻质土抗压强度<br/>Fig.6 Compressive strength of foamed lightweight soil under different water saturation conditions

图6 不同饱水状态下泡沫轻质土抗压强度
Fig.6 Compressive strength of foamed lightweight soil under different water saturation conditions

图7 不同土掺量泡沫轻质土软化系数<br/>Fig.7 Softening coefficient of foamed lightweight soil with different soil contents

图7 不同土掺量泡沫轻质土软化系数
Fig.7 Softening coefficient of foamed lightweight soil with different soil contents

图8 干湿循环下干质量损失率<br/>Fig.8 Dry mass decrease rate of dry wet cycle

图8 干湿循环下干质量损失率
Fig.8 Dry mass decrease rate of dry wet cycle

图9 干湿循环下湿质量增加率<br/>Fig.9 Wet mass increase rate of dry wet cycle

图9 干湿循环下湿质量增加率
Fig.9 Wet mass increase rate of dry wet cycle

图10 不同掺土量泡沫轻质土随干湿循环强度比<br/>Fig.10 Dry-wet cycling strength ratio of light weight soil with different amounts of soil

图10 不同掺土量泡沫轻质土随干湿循环强度比
Fig.10 Dry-wet cycling strength ratio of light weight soil with different amounts of soil

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备注

引言

1 试验用原材料与配合比

2 力学性能

3 耐久性试验

4 结论

期刊信息