基于改进FHP模型的掺火山灰RCC加速养护方法

An Accelerated Curing Method of RCC with Pozzolan Based on Modified FHP Model

摘要:

巴基斯坦巴沙大坝工程采用掺天然火山灰的碾压混凝土（RCC），为了快速推定RCC的1 a抗压强度，测试了不同温度下天然火山灰与水泥复合胶凝材料的表观活化能，并尝试采用Freiesleben-Hansen-Pedersen（FHP）模型计算不同加速养护制度下的等效标准养护龄期（等效龄期）.结果表明：复合胶凝材料在70~90 ℃下的表观活化能通过试验难以测得，但基于表观活化能的温度依存性，可通过对其5~60 ℃下表观活化能的一元线性回归计算得出，并获得改进FHP模型；基于工程现场测试结果，与FHP模型相比，采用改进FHP模型计算出的90 ℃等效龄期与实测等效龄期的偏差率均在6.7%以内.

Abstract:

Roller Compacted Concrete （RCC） incorporating natural pozzolan was used in Bashan Dam project in Pakistan. To rapidly estimate the 1 a compressive strength of the RCC， the apparent activation energy of the composite cementitious material made from natural pozzolan and cement was tested at different temperatures. An attempt was made to use the Freiesleben-Hansen-Pedersen （FHP） model to calculate the equivalent standard curing age（equivalent age） under different accelerated curing regimes. The results indicate that the apparent activation energy of the composite cementitious material at 70-90 ℃ is difficult to be measured experimentally. However， based on the temperature dependence of the apparent activation energy， it can be calculated through univariate linear regression of the apparent activation energy at 5-60 ℃， leading to an improved FHP model. Based on field test results at the project site， compared to the FHP model， the deviation rate of the equivalent age calculated at 90 ℃ using the improved FHP model from the measured equivalent age is controlled to be within 6.7%.