Cement Hydration Rate of Ordinarily and Internally Cured Concretes

Abstract

In the present paper, adiabatic temperature rise test was used to evaluate the effect of internal curing on cement hydration rate and final degree of hydration in normal and high strength concretes. In the experiments, emphases were placed on the impacts of internal curing and water to cementitious material ratio on the adiabatic temperature rise characteristics. Two kinds of concrete, ordinarily cured concrete and internally cured concrete were used in the experiments. In each kind, four concrete mixtures with water to cementitious material ratios of 0.20, 0.30, 0.43 and 0.62 were used. The test results show that internal curing with PSLWA increases temperature rise of concrete, whatever the concrete strength is low or high. Internal curing can not only increase the ultimate temperature rise, but also increase the rate of temperature rise. Internal curing can obviously improve the cement hydration behavior compared with the concrete without internal curing. The improvements on cement hydration may present in two. One is the hydration rate in the second stage is increased; another is the final cement hydration degree is increased. For internally cured concrete, the water used to calculate the water to binder ratio can be simply summing the mixing water and internal curing water together when calculate the final cement hydration degree. The proposed cement hydration rate model can well predict developing of cement hydration degree for both ordinarily and internally cured concretes.

Exploring Exact Effects of Various Factors on Chloride Diffusion in Cracked Concrete: ABAQUS-Based Mesoscale Simulations

“…The porosity and pore structure of concrete are closely related to the water–cement ratio ( W / C ) and the degree of hydration ( α ) [ 30 ]. It has been reported that the degree of hydration can reach as high as 0.89 when the W / C is 0.3 [ 31 ]. The increase in porosity leads to a decrease in concrete compactness, making it easier for chloride ions to penetrate into the concrete.…”

Use of Cement Hydration Heat as Heating Resource in Curing of Precast Concrete - Temperature Rise Simulation

“…Changing the actual age of adiabatic temperature rise test into the equivalent age according to the temperature history, the degree of cement hydration obtained by Eq. ( 3) can be fitted as below (Pane and Hansen 2002;Zhang et al 2009;Wang et al 2018).…”

“…Cement hydration parameters of each concrete determined by the adiabatic temperature rise tests and the mineral compositions of the concrete, along with density, specific heat, elastic modulus, and compressive strength of each concrete, are listed in Table 4. Details regarding the adiabatic temperature rise tests of the three concretes can be found in a previous publication (Wang et al 2018). Figure 4 displays a comparison of the degree of cement hydration and equivalent age diagrams between test results and the model prediction [Eq.…”

Design of an Adiabatic Calorimeter for Cementitious Mixtures by Multi-Objective Optimization

“…Likewise, it was implemented the calorimeter designed to perform heat of hydration measurements on cement paste samples. The novelty of this work is to display that the calorimeter was developed using concurrent design (optimization algorithms) unlike existing calorimeters implemented [13][14][15][16]. It is expected that this work will be one of the first to develop optimized calorimeters for cement mixtures [17].…”