Influences of admixtures on the workability and strength of high performance concrete （HPC） are in- vestigated. The types of investigated admixtures include naphthalene series high range water reducing agent, polyca...Influences of admixtures on the workability and strength of high performance concrete （HPC） are in- vestigated. The types of investigated admixtures include naphthalene series high range water reducing agent, polycarboxlic series high range water reduce agent and sodium sulfate hardening accelerating agent. Two kinds of curing condition, namely steam curing condition and standard curing condition, are adopted. The result shows that HPC, added with polycarboxlic series of high performance water reducer, has high workability and strength, while sodium sulfate accelerating agent causes poor workability and low strength. Thus for vapor-cured HPC and its formulations, naphthalene series high range water reducing agent with less sodium sulfate should be given pri- ority. Therefore, the differences of curing conditions should be considered when selecting HPC admixtures.展开更多
Polypropylene fiber and expansive agent are used in airport concrete to improve its shrinkage cracking resistance and mechanical properties.The concrete specimens with amount content of polypropylene fiber or expansiv...Polypropylene fiber and expansive agent are used in airport concrete to improve its shrinkage cracking resistance and mechanical properties.The concrete specimens with amount content of polypropylene fiber or expansive agent or both of them are prepared.The morphology of specimens is observed by scanning electron microscope,the time when the first crack occurred is recorded through slap test,and the mechanical properties such as compressive strength and impact energies of concrete are measured.The results show that polypropylene fiber in concrete can reduce the shrinkage and delay the first crack,improve the impact resistance obviously,and improve the compressive strength slightly.Expansive agent can compensate the shrinkage and reduce cracks of concrete pavement markedly,and improve the mechanical properties of concrete pavement slightly.The study provides recommendations for cracking control of airport concrete pavement in the future.展开更多
基金Supported by the National Basic Research Programe of China("973"Program)(2009CB623203)the Construction Department of Zhejiang Province Foundation(1006)+1 种基金the Education Department of Zhejiang Province Foundation(Y200909029)the Doctoral Innovation Foundation of Nanjing University of Aeronautics andAstronautics(BCXJ07-04)~~
文摘Influences of admixtures on the workability and strength of high performance concrete （HPC） are in- vestigated. The types of investigated admixtures include naphthalene series high range water reducing agent, polycarboxlic series high range water reduce agent and sodium sulfate hardening accelerating agent. Two kinds of curing condition, namely steam curing condition and standard curing condition, are adopted. The result shows that HPC, added with polycarboxlic series of high performance water reducer, has high workability and strength, while sodium sulfate accelerating agent causes poor workability and low strength. Thus for vapor-cured HPC and its formulations, naphthalene series high range water reducing agent with less sodium sulfate should be given pri- ority. Therefore, the differences of curing conditions should be considered when selecting HPC admixtures.
基金Supported by the High-Level Talent Funding and Construction System of Jiangsu Province(JZ-010,2013ZD12)the China Post-Doctoral Science Foundation(2014M551588,1301057B)the National High-Tech Research and Development Program of China("863"Program)(2009AA03Z508)
文摘Polypropylene fiber and expansive agent are used in airport concrete to improve its shrinkage cracking resistance and mechanical properties.The concrete specimens with amount content of polypropylene fiber or expansive agent or both of them are prepared.The morphology of specimens is observed by scanning electron microscope,the time when the first crack occurred is recorded through slap test,and the mechanical properties such as compressive strength and impact energies of concrete are measured.The results show that polypropylene fiber in concrete can reduce the shrinkage and delay the first crack,improve the impact resistance obviously,and improve the compressive strength slightly.Expansive agent can compensate the shrinkage and reduce cracks of concrete pavement markedly,and improve the mechanical properties of concrete pavement slightly.The study provides recommendations for cracking control of airport concrete pavement in the future.
