Evaluation of Lignosulfonate Based Retarders for Thickening Time as a Function of Dosage and Temperature

2021 ◽  
Author(s):  
Justin Montgomery ◽  
Timothy McNally ◽  
Jay Hunger ◽  
Sreedhar Subramanian
Keyword(s):  
Portland Cement ◽  
Time Response ◽  
Temperature Relationship ◽  
Optimal Dosage ◽  
Significant Finding ◽  
Cement Slurry ◽  
Temperature Range ◽  
Exponential Increase

Abstract The retardation of class H Portland cement using lignosulfonates was investigated in the temperature range between 54°C and 153°C. Lignosulfonates with varying extent of modification was used in the study, and the optimum retarder dosage and temperature range to achieve desired thickening time was identified for different lignosulfonate types (non-modified, modified and highly modified). In general, a linear thickening response was observed at low retarder dosage, while a near exponential increase in thickening time response was observed at higher dosages. Defining the retarder dosage temperature relationship is essential for proper cement slurry design for securing desired placement of cement slurry. A significant finding is that the thickening time responses trend from near linear at low dosages, transitioning to near exponential at higher dosages. The observed results varied depending on the extent of modification performed on the lignosulfonate retarder. Pure lignosulfonate retarders produce optimal dosage response from 54°C to 97°C. Modified retarders work best in the range of 97°C to 118°C. While highly modified retarders perform best in the range of 118°C to 153°C. Defining the retarder dosage temperature relationship is essential for proper cement slurry design for securing desired placement of cement slurry.

Thermal analysis of high-performance mortar containing burnt clay shale as a partial portland cement replacement in the temperature range up to 1000 °C

2016 ◽  
Vol 41 (1) ◽  
pp. 54-64 ◽  
Author(s):  
Anton Trník ◽  
Lenka Scheinherrová ◽  
Tereza Kulovaná ◽  
Pavel Reiterman ◽  
Eva Vejmelková ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Portland Cement ◽  
High Performance ◽  
Clay Shale ◽  
Cement Replacement ◽  
Temperature Range ◽  
Burnt Clay

Study of Mass Changes of Cement Pastes as a Function of Age Using Thermogravimetry

2015 ◽  
Vol 824 ◽  
pp. 43-47
Author(s):  
Lenka Scheinherrová ◽  
Anton Trník ◽  
Tereza Kulovaná ◽  
Robert Černý
Keyword(s):  
Czech Republic ◽  
Portland Cement ◽  
Heating Rate ◽  
Calcium Silicate ◽  
Calcium Silicate Hydrate ◽  
Argon Atmosphere ◽  
Mass Change ◽  
Cement Pastes ◽  
The Czech Republic ◽  
Temperature Range

We study the hydration and pozzolanic reactions of cement pastes made from Portland cement (CEM I 32.5 R) from the Czech Republic as a function of age, using thermogravimetry. The measurements are done for 2, 7, 28, 90, and 180 days cured samples in order to monitor the rate of hydration. The investigation is performed in the temperature range from 25 °C to 1000 °C with a heating rate 5 °C/min in an argon atmosphere. The mass change during the decomposition of calcium silicate hydrate gels, portlandite, and calcite are determined, and the changes in the portlandite amount are estimated in dependence on the time of hydration.

Effect of Volcanic Rock Powder on Performance of Foamed Concrete

2014 ◽  
Vol 1033-1034 ◽  
pp. 887-891
Author(s):  
Kui Fan Su ◽  
Bo Jiang ◽  
Jiang Shan Lian ◽  
Pei Cheng Qin ◽  
Si Zhi He ◽  
...  
Keyword(s):  
Portland Cement ◽  
Volcanic Rock ◽  
Dry Density ◽  
Foam Concrete ◽  
Cement Slurry ◽  
Rock Powder ◽  
Foamed Concrete ◽  
Powder Addition ◽  
Powder Content ◽  
Curing Age

Foamed concrete is prepared by the use of volcanic rock powder and ordinary portland cement and by means of chemical foaming method. The chemical composition and morphology of volcanic rock powder are analyzed,and the effect of volcanic rock powder addition into the portland cement slurry on the properties of foamed concrete is discussed.The results that the properties of the foam concrete could be prepared by controlling the addition of the volcanic rock powder content is 20%, The Compressive strength is as high as 1.36Mpa. The thermal conductivity is 0.048W/(m·K) and the dry density is 254kg/m3 for 28 days curing age. The main compositions of volcanic rock powder is SiO2 and the volcanic rock has a large number of closed and open pores.

Effect of the hydration rate and microstructure of Portland cement slurry on hydrostatic pressure transfer

2019 ◽  
Vol 352 ◽  
pp. 251-261 ◽  
Author(s):  
Kaiqiang Liu ◽  
Xiaowei Cheng ◽  
Xianshu Gao ◽  
Xingguo Zhang ◽  
Xiaoyang Guo ◽  
...  
Keyword(s):  
Hydrostatic Pressure ◽  
Portland Cement ◽  
Cement Slurry ◽  
Hydration Rate

scholarly journals Predictive Hydration Model of Portland Cement and Its Main Minerals Based on Dissolution Theory and Water Diffusion Theory

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 595
Author(s):  
Tianqi Qi ◽  
Wei Zhou ◽  
Xinghong Liu ◽  
Qiao Wang ◽  
Sifan Zhang
Keyword(s):  
Portland Cement ◽  
Cement Hydration ◽  
Diffusion Theory ◽  
Moisture Diffusion ◽  
Test Results ◽  
Cement Slurry ◽  
Element Analysis ◽  
Prediction Ability ◽  
Hydration Effect ◽  
Hydration Model

Efficient and accurate cement hydration simulation is an important issue for predicting and analyzing concrete’s performance evolution. A large number of models have been proposed to describe cement hydration. Some models can simulate the test results with high accuracy by constructing reasonable functions, but they are based on mathematical regression and lack of physical background and prediction ability. Other models, such as the famous HYMOSTRUC model and CEMHYD3D model, can predict the hydration rate and microstructure evolution of cement based on its initial microstructure. However, this kind of prediction model also has some limitations, such as the inability to fully consider the properties of cement slurry, or being too complicated for use in finite element analysis (FEA). In this study, the hydration mechanisms of the main minerals in Portland cement (PC) are expounded, and the corresponding hydration model is built. Firstly, a modified particle hydration model of tricalcium silicate (C3S) and alite is proposed based on the moisture diffusion theory and the calcium silicate hydrate (C-S-H) barrier layer hypothesis, which can predict the hydration degree of C3S and alite throughout the age. Taking the hydration model of C3S as a reference, the hydration model of dicalcium silicate (C2S) is established, and the synergistic hydration effect of C3S and C2S is calibrated by analyzing the published test results. The hydration model of tricalcium aluminate(C3A)-gypsum system is then designed by combining the theory of dissolution and diffusion. This model can reflect the hydration characteristics of C3A in different stages, and quantify the response of the hydration process of C3A to different gypsum content, water–cement ratio, and particle size distribution. Finally, several correction coefficients are introduced into the hydration model of the main mineral, to consider the synergistic hydration effect among the minerals to some extent and realize the prediction of the hydration of PC.

Life Cycle Assessment of Cement Clinker Production Using Coal Gangue as Alternative Raw Material and Fuel

2015 ◽  
Vol 814 ◽  
pp. 435-440 ◽  
Author(s):  
Jia Ping Cui ◽  
Yu Liu ◽  
Zhi Hong Wang ◽  
Xian Zheng Gong ◽  
Feng Gao ◽  
...  
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Portland Cement ◽  
Coal Gangue ◽  
Raw Material ◽  
Cement Clinker ◽  
Optimal Dosage ◽  
Portland Cement Clinker ◽  
Almost All ◽  
Clinker Production

Life cycle assessment (LCA) was carried out to quantify and analyze the environmental impact and benefit caused by the utilization of coal gangue as alternative raw material and fuel in cement clinker production. The optimal dosage of coal gangue was determined by comparing among different mixing amount scenarios and Portland cement clinker (clinker without adding any waste) considering the phases of coal gangue disposal, transportation, and raw meal grinding and clinker calcination. The results showed that: 1) After adding coal gangue to the raw meal, almost all the considered environmental impacts of cement clinker including human toxicity potential, photochemical smog potential, especially abiotic depletion potential decreased significantly. However, global warming potential and acidification potential increased slightly in comparison with Portland cement clinker. 2) Compared with the Portland cement clinker, the single environmental indicator reduced after adding coal gangue and the indicator decreased gradually with the dosage increasing.

Research on the Influence of Water Storage Medium on early Planting Performance of Portland Cement Foamed Concrete

2021 ◽  
Vol 1036 ◽  
pp. 395-401
Author(s):  
Xiao Li ◽  
Tong Wang
Keyword(s):  
Portland Cement ◽  
Water Storage ◽  
Infiltration Rate ◽  
Optimal Dosage ◽  
Planting Material ◽  
Influence Of Water ◽  
Foamed Concrete ◽  
New Type ◽  
And Performance ◽  
Solid Liquid

Adding sap particle, Portland cement foamed concrete was studied to manufacture a new type of planting material. The pH, porosity, permeable capacity, infiltration rate and water storage were tested for evaluating the performance of foamed concrete. Solid-liquid extraction method and image binaryzation were used to study the pH and porosity of foamed concrete. A kind of self-made permeable device was also used in this paper. It was found that the pH of foamed concrete could be decreased by sap particles absorbed the boric acid solution in 14 d. For the foaming effect of fresh concrete was disturbed by liquid from sap particles, the porosity of foamed concrete was increased and then decreased. Seepage channels could be formed in foamed concrete when sap particles shrunk for releasing liquid and they also would be block for sap particles expanding when water permeated into foamed concrete. The permeable capacity and infiltration rate were decreased with increasing sap particles. The water storage of foamed concrete was fluctuated with sap particles increasing but more than that without sap particles. The optimal dosage of sap particles was 0.3wt% of binder material in this study. At the dosage, the minimal pH of foamed concrete could be obtained and performance of that would be good to plant, such as permeable capacity, infiltration rate and water storage.

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