In order to improve the early-age cracking resistance of concrete, different types of superplasticizers are used. Two types of polycarboxlic salt/acid superplasticizers and one retarding naphthalene superplasticizer a...In order to improve the early-age cracking resistance of concrete, different types of superplasticizers are used. Two types of polycarboxlic salt/acid superplasticizers and one retarding naphthalene superplasticizer are selected to investigate the influence of superplasticizers on the early-age cracking resistance of the concrete by using the slab test and the temperature-stress test. The results show that the polycarboxlic salt/acid superplasticizer cannot always improve the cracking resistance capacity of the concrete compared with the naphthalene superplasticizer, which is related to the chemical structure of the polycarboxlic salt/acid superplasticizer. High plastic tensile strength and dynamic elastic modulus at the early stage are beneficial to avoid cracking, and low hydration heat is also helpful. The evolutions of the drying shrilakage stress and the hydration heat temperature stress varying with time can be comprehensively evaluated by means of the slab test and the temperature stress test.展开更多
目的建立祖师麻药材定量测定方法。方法采用高效液相色谱法。色谱柱为Phenomenex Luna C18(250mm×4.6mm,5μm);流动相:甲醇-0.5%醋酸溶液(25∶75);体积流量:1.0mL/min;检测波长:327nm;柱温:30℃;进样量:10μL。结果祖师麻甲素在0.1...目的建立祖师麻药材定量测定方法。方法采用高效液相色谱法。色谱柱为Phenomenex Luna C18(250mm×4.6mm,5μm);流动相:甲醇-0.5%醋酸溶液(25∶75);体积流量:1.0mL/min;检测波长:327nm;柱温:30℃;进样量:10μL。结果祖师麻甲素在0.1467～2.2005μg线性关系良好(r=0.9999),平均回收率为100.88%,RSD为1.60%(n=6)。结论本法操作简便、准确、重现性好,可用于祖师麻药材的质量控制。展开更多
基金International Collaborative Research Project of Sika Technology AG of Switzerland,the Traffic Scientific Research Project in Jiangsu Province (No. 2010Y01)
文摘In order to improve the early-age cracking resistance of concrete, different types of superplasticizers are used. Two types of polycarboxlic salt/acid superplasticizers and one retarding naphthalene superplasticizer are selected to investigate the influence of superplasticizers on the early-age cracking resistance of the concrete by using the slab test and the temperature-stress test. The results show that the polycarboxlic salt/acid superplasticizer cannot always improve the cracking resistance capacity of the concrete compared with the naphthalene superplasticizer, which is related to the chemical structure of the polycarboxlic salt/acid superplasticizer. High plastic tensile strength and dynamic elastic modulus at the early stage are beneficial to avoid cracking, and low hydration heat is also helpful. The evolutions of the drying shrilakage stress and the hydration heat temperature stress varying with time can be comprehensively evaluated by means of the slab test and the temperature stress test.
文摘目的建立祖师麻药材定量测定方法。方法采用高效液相色谱法。色谱柱为Phenomenex Luna C18(250mm×4.6mm,5μm);流动相:甲醇-0.5%醋酸溶液(25∶75);体积流量:1.0mL/min;检测波长:327nm;柱温:30℃;进样量:10μL。结果祖师麻甲素在0.1467～2.2005μg线性关系良好(r=0.9999),平均回收率为100.88%,RSD为1.60%(n=6)。结论本法操作简便、准确、重现性好,可用于祖师麻药材的质量控制。
