Prediction of the Effect of GGBFS on the Hydration of Cement Using Extended CEMHYD3D Model | Chapter 2 | Theory and Applications of Engineering Research Vol. 5

The study presents important findings on predicting the behavior of a Portland cement-based mixture, specifically regarding hydration. Supplementary cementitious materials (SCMs) such as ground granulated blast furnace slag (GGBFS), often called slag cement, fly ash (FA), and silica fume (SF) are widely used in cementitious composites due to their durability, environmental friendliness, and minimal cost. Portland cement is usually substituted with granulated blast furnace slag (GGBFS) to make a blended cement. A slag-blended cement has a more complicated hydration process than Portland cement due to the interactions between the slag reaction and the hydration of Portland cement in the cementitious systems. Understanding the effect of slag substitution on the hydration of cement is still challenging. To achieve this, the extended CEMHYD3D model was employed to predict the hydration of a slag-blended cement. An OPC as a reference cement confirmed to ASTM C 150 and a slag confirmed to ASTM C 989 standard requirements were used in this study. The simulation was done with cement paste samples made with various w/c ratios and different slag substitution levels, in which the interaction between the hydration of Portland cement and the reaction of slag was considered. The prediction model has been validated with experimental results and verified to be successful in predicting the hydration of slag-blended cement. The consideration of the chemical composition of slag improves the predictability of hydration in cement, and the same method was applied in this model. Both in the early age and up to the age of 90 days, the hydration of slag-blended cement can be predicted with the proposed model.

Author(s) Details:

Andualem Yadeta,
Department of Civil Engineering, Delhi Technological University, Delhi 110042, India and Department of Construction Technology and Management, Madda Walabu University, Bale Robe 242, Ethiopia.

Pradeep Goyal,
Department of Civil Engineering, Delhi Technological University, Delhi 110042, India.

Raju Sarkar,
Department of Civil Engineering, Delhi Technological University, Delhi 110042, India.

Please see the link here: https://stm.bookpi.org/TAER-V5/article/view/13293

Possibilities of Solving the Stability of Salt Strata Penetrated by Drilling: A Descriptive Study| Chapter 6 | Emerging Challenges in Environment and Earth Science Vol. 3

The rendering of oil structures apparent in the deep layers in Romania limits the penetration of some thick salt deposits (500-3,000 m) positioned above structures with petroleum potential (6,000 m). Drilling through these salt deposits is a major risk both during construction (drilling, cementing) and thereafter to ensure the wells' stability and dependability. These considerations shaped the approach to the salt deformation behaviour study challenge. The purpose of this article is to examine the following: salt behaviour deformation; establishment of the required parameters to ensure the stability of the drillings until bore-hole lining (particularly the secondary stress state around the drilling, the density of the drilling fluid in relation to temperature, respectively the depth), and also after casing (type of cement pastes, nature, quality, and pipe dimensions), namely the reliabilit The findings may aid in the selection of various options for guaranteeing the stability of boreholes that reach salt layers.

Author(s) Details:

Mihaela Toderas,
Department of Mining Engineering, Surveying and Constructions, University of Petrosani, Petrosani, 332006, Romania.

Please see the link here: https://stm.bookpi.org/ECEES-V3/article/view/6689

Investigation of the Effect of Aggregate/Cement and Water/Cement Ratios on Concrete Workability | Chapter 1 | New Visions in Science and Technology Vol. 6

 Fresh concrete's workability is determined by its consistency, mobility, and compactability. Several factors influence concrete workability, but the effect of aggregate/cement (AG/CM) and water/cement (W/C) ratios is the subject of this study. The study's goals are to assess the aggregate/cement and water/cement ratios of freshly formed concretes, as well as the influence of different mix ratios on concrete workability (MC1, MC2, MC3, MC4, MC5, and MC6). To achieve this, slump, compacting factor, and modified vebe tests were carried out in an environment with a temperature of 26-30°C, 92 percent relative humidity, and little wind. Fresh concretes with AG/CM ratios of 6.1, 5.0, 4.0, 3.0, 2.5, 2.1 and W/C ratios of 0.6, 0.55, 0.5, 0.45, 0.4, and 0.38 were used in the testing. The data show that when the AG/CM and W/C ratios decline, slump and compacting factors rise, meaning that as workability increases, the AG/CM and W/C ratios decrease as well. The results also revealed that as the AG/CM and W/C ratios increase, the Vebe time decreases, implying that vibrating concretes with low AG/CM (3.0) and W/C (0.45) ratios is easier. As the W/C ratio rises, the AG/CM ratio climbs as well. The regression coefficients (R2) obtained from the Slump-AG/CM, Slump-W/C, Compacting factor-AG/CM, Compacting factor-W/C, Vebe time-AG/CM, and Vebe time-W/C curves are 96.7 percent, 98.8 percent, 99.4 percent, 99.3 percent, 99.1 percent, and 99.4 percent, indicating a clear relationship between them.

Author (S) Details

 

Joseph Chukwuka Okah

Department of Building Technology, Port Harcourt Polytechnic, Rivers State, Nigeria.

N. J. Elekima Amos

Department of Building Technology, Port Harcourt Polytechnic, Rivers State, Nigeria.

View Book :- https://stm.bookpi.org/NVST-V6/article/view/4128