Brittleness of Concrete under Different Curing Conditions
In order to shorten construction periods, concrete is often cured using steam and is loaded at an early age. This changes the performance and even the durability of the concrete compared to concrete that has been cured under normal conditions. Thus, the pattern and the mechanism of concrete performa...
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MDPI AG
2021-12-01
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| Online Access: | https://www.mdpi.com/1996-1944/14/24/7865 |
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| author | Shuai Zhang Bing Han Huibing Xie Mingzhe An Shengxu Lyu |
| author_facet | Shuai Zhang Bing Han Huibing Xie Mingzhe An Shengxu Lyu |
| author_sort | Shuai Zhang |
| collection | DOAJ |
| description | In order to shorten construction periods, concrete is often cured using steam and is loaded at an early age. This changes the performance and even the durability of the concrete compared to concrete that has been cured under normal conditions. Thus, the pattern and the mechanism of concrete performance change under different curing conditions, and loading ages are of great significance. The development of brittleness under different curing conditions and loading ages was studied. The evaluation methods that were used to determine concrete brittleness were expounded. Steam, standard, and natural curing conditions were carried out on single-side notched concrete beams as well as on a concrete prism and cubic blocks. The compressive strength and splitting tensile strength of the concrete blocks along with the fracture performance of the concrete beams were tested after 3, 7, 28, and 90 days. The steam curing condition significantly improved the strength of concrete before 28 days had passed, and the standard curing condition improved the strength of concrete after 28 days. Based on the experimental fracture parameters, a two-parameter fracture model was applied to study the development of fracture toughness <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msubsup><mi>K</mi><mrow><mi mathvariant="italic">IC</mi></mrow><mi>S</mi></msubsup></mrow></semantics></math></inline-formula>, critical crack tip opening displacement <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi mathvariant="italic">CTOD</mi></mrow><mi>c</mi></msub></mrow></semantics></math></inline-formula>, and critical strain energy release rate <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msubsup><mi>G</mi><mrow><mi mathvariant="italic">IC</mi></mrow><mi>S</mi></msubsup></mrow></semantics></math></inline-formula> with hydration age under different curing conditions. With respect to long-term performance, the standard curing condition was better at resisting concrete crack propagations than the steam curing condition was. The characteristic length <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>l</mi><mrow><mi mathvariant="italic">ch</mi></mrow></msub></mrow></semantics></math></inline-formula> and the material length <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>Q</mi></semantics></math></inline-formula> under the three curing conditions and the long-term development of brittleness in the concrete indicated that steam curing increased the concrete brittleness. Considering the effects of the curing condition and the loading age, a time-dependent concrete fracture toughness model was established, and the predicted value of the model was verified against the measured value. The results indicated that the model was able to accurately predict the fracture toughness with an error rate of less than 16%. |
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| language | English |
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| spelling | doaj.art-a12b7bde1dcb4b9da9c906eb0a60e9df2023-11-23T09:24:09ZengMDPI AGMaterials1996-19442021-12-011424786510.3390/ma14247865Brittleness of Concrete under Different Curing ConditionsShuai Zhang0Bing Han1Huibing Xie2Mingzhe An3Shengxu Lyu4School of Civil Engineering, Beijing Jiaotong University, Beijing 100044, ChinaSchool of Civil Engineering, Beijing Jiaotong University, Beijing 100044, ChinaSchool of Civil Engineering, Beijing Jiaotong University, Beijing 100044, ChinaSchool of Civil Engineering, Beijing Jiaotong University, Beijing 100044, ChinaSchool of Civil Engineering, Beijing Jiaotong University, Beijing 100044, ChinaIn order to shorten construction periods, concrete is often cured using steam and is loaded at an early age. This changes the performance and even the durability of the concrete compared to concrete that has been cured under normal conditions. Thus, the pattern and the mechanism of concrete performance change under different curing conditions, and loading ages are of great significance. The development of brittleness under different curing conditions and loading ages was studied. The evaluation methods that were used to determine concrete brittleness were expounded. Steam, standard, and natural curing conditions were carried out on single-side notched concrete beams as well as on a concrete prism and cubic blocks. The compressive strength and splitting tensile strength of the concrete blocks along with the fracture performance of the concrete beams were tested after 3, 7, 28, and 90 days. The steam curing condition significantly improved the strength of concrete before 28 days had passed, and the standard curing condition improved the strength of concrete after 28 days. Based on the experimental fracture parameters, a two-parameter fracture model was applied to study the development of fracture toughness <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msubsup><mi>K</mi><mrow><mi mathvariant="italic">IC</mi></mrow><mi>S</mi></msubsup></mrow></semantics></math></inline-formula>, critical crack tip opening displacement <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi mathvariant="italic">CTOD</mi></mrow><mi>c</mi></msub></mrow></semantics></math></inline-formula>, and critical strain energy release rate <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msubsup><mi>G</mi><mrow><mi mathvariant="italic">IC</mi></mrow><mi>S</mi></msubsup></mrow></semantics></math></inline-formula> with hydration age under different curing conditions. With respect to long-term performance, the standard curing condition was better at resisting concrete crack propagations than the steam curing condition was. The characteristic length <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>l</mi><mrow><mi mathvariant="italic">ch</mi></mrow></msub></mrow></semantics></math></inline-formula> and the material length <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>Q</mi></semantics></math></inline-formula> under the three curing conditions and the long-term development of brittleness in the concrete indicated that steam curing increased the concrete brittleness. Considering the effects of the curing condition and the loading age, a time-dependent concrete fracture toughness model was established, and the predicted value of the model was verified against the measured value. The results indicated that the model was able to accurately predict the fracture toughness with an error rate of less than 16%.https://www.mdpi.com/1996-1944/14/24/7865concretecuring conditionloading agefracture propertybrittleness |
| spellingShingle | Shuai Zhang Bing Han Huibing Xie Mingzhe An Shengxu Lyu Brittleness of Concrete under Different Curing Conditions Materials concrete curing condition loading age fracture property brittleness |
| title | Brittleness of Concrete under Different Curing Conditions |
| title_full | Brittleness of Concrete under Different Curing Conditions |
| title_fullStr | Brittleness of Concrete under Different Curing Conditions |
| title_full_unstemmed | Brittleness of Concrete under Different Curing Conditions |
| title_short | Brittleness of Concrete under Different Curing Conditions |
| title_sort | brittleness of concrete under different curing conditions |
| topic | concrete curing condition loading age fracture property brittleness |
| url | https://www.mdpi.com/1996-1944/14/24/7865 |
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