Article
Construction & Building Technology
Saulo Rocha Ferreira, Neven Ukrainczyk, Keoma Defaveri do Carmo e Silva, Luiz Eduardo Silva, Eduardo Koenders
Summary: The addition of Microcrystalline Cellulose (MCC) can increase the compressive strength and stiffness of both Portland cement and geopolymer pastes at 7 days, but may reduce the mechanical properties of geopolymer paste after 28 days due to MCC degradation. In addition, the addition of MCC can accelerate the setting time of geopolymer by 15%, while causing a considerable delay effect on cement paste.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Chemistry, Physical
Renhui Gao, Wei Yang, Zhenhua Duan, Hui Liu, Qi Deng, Minqi Hua
Summary: This study investigated the effect of different calcium sources on the mechanical properties and microstructures of geopolymers. The results showed that the optimal incorporation of 5% calcium source significantly improved the compressive strength and flexural strength of geopolymers. The incorporation of calcium source accelerated the geopolymerization reaction and promoted a more densified microstructure, resulting in improved strength. However, excessive calcium source hindered the hydration process and weakened the workability and strength of geopolymers.
Article
Construction & Building Technology
Vineet Shah, Anuj Parashar, Allan Scott
Summary: This study examines the influence of different carbonate and non-carbonate sources on the performance of Portland metakaolin cement binder, showing that the additives have an impact on early strength but minimal effect on later compressive strength; the absence of carbonate ions may lead to the formation of stratlingite, speculated to contribute to later age strength development. No significant difference was observed in porosity, electrical resistivity, or carbonation resistance between binders containing carbonate or non-carbonate sources at later age.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Chemistry, Physical
Saixin Wang, Zheng Niu, Dongmei Jin, Jian He, Yuandong Mu, Guotian Ye
Summary: This paper investigates the effect of the reactivity of calcium and silicon in waste cement on the hydrothermal synthesis of xonotlite. The study finds that calcination of hydrated cement improves its reactivity, thus affecting the formation rate of xonotlite.
Article
Construction & Building Technology
Melaku N. Seifu, Jun Kil Park, Taek Hee Han, Solmoi Park, Min Ook Kim
Summary: This study investigated the properties of ternary cement containing oyster shell powder. The results showed that the addition of oyster shell formed compounds that improved the stability of the samples, and the consumption of oyster shell in ternary cement was influenced by other materials.
CASE STUDIES IN CONSTRUCTION MATERIALS
(2022)
Article
Construction & Building Technology
Semion Zhutovsky, Andrei Shishkin
Summary: Recycling of concrete waste is crucial for reducing environmental impact, and the fine aggregate component of concrete waste can potentially be completely recovered into new clinker through thermal treatment. This research demonstrates the potential for complete recycling of concrete fines for low carbon footprint cement production by investigating phase transformations in hydrated cement paste upon heating. The results offer promising prospects for sustainable concrete waste management.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Construction & Building Technology
Sreejith Krishnan, Abhishek Singh, Shashank Bishnoi
Summary: This study investigates the influence of alkali addition on the hydration, phase assemblage, and strength development in ordinary portland cement (OPC) and limestone-calcined clay cement (LC3) produced with 50% clinker replacement. The alkalinity of OPC and LC3 was increased using four different alkali salts, resulting in an acceleration of early age hydration and strength development in both systems. However, increasing the alkalinity was also observed to reduce later age clinker hydration and strength development.
JOURNAL OF MATERIALS IN CIVIL ENGINEERING
(2021)
Article
Geochemistry & Geophysics
Joan Gutierrez-Leon, Jordi Cama, Ignasi Queralt, Jose Antonio Jimenez, Josep M. Soler
Summary: This study utilized experiments and modeling to identify that the main reactions were the dissolution of cement and rock, leading to the precipitation of gypsum, aragonite, brucite, and Fe-and Al-poorly crystalline phases. Additionally, Cd, Ni, and Zn hydroxides, Zn carbonates, and the adsorption or co-precipitation of Cu and As on specific minerals were observed as part of the geochemical processes caused by AMD exposure.
APPLIED GEOCHEMISTRY
(2021)
Article
Construction & Building Technology
Ehsan Negahban, Ali Bagheri, Jay Sanjayan
Summary: This study investigated the microstructural characteristics of geopolymer concrete and ordinary Portland cement concrete, revealing their correlation with strength and durability. The results showed that the pore volume of geopolymer concrete was significantly higher than that of ordinary Portland cement, and variations in parameters could control the mechanical properties and durability of the materials.
CEMENT & CONCRETE COMPOSITES
(2021)
Article
Construction & Building Technology
Jiahui Zhu, Zanqun Liu, Keren Zheng, Ju Huang, Yu Cui
Summary: In this paper, the reaction kinetics of the early hydration of MgSO4.7H2O + Portland cement clinker (MPC) was compared with CaSO4.2H2O + Portland cement clinker (OPC) using isothermal calorimetry, chemical shrinkage and solid-liquid phase analysis. The results showed that MgSO4.7H2O had a more pronounced retarding effect on Portland cement clinker hydration than CaSO4.2H2O. The presence of Mg (OH)2 and CaSO4.2H2O prevented the flash-set of clinker and resulted in a slower hydration rate of MPC compared to OPC.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Green & Sustainable Science & Technology
Jiaqi Xu, Elina Ceballos, Jordi Cama, Josep M. Soler
Summary: CO2 geological storage is a potential solution to reduce atmospheric CO2 concentration. The interaction between CO2-rich water, cement, and rock formations can lead to cement and rock alteration and the precipitation of secondary minerals. However, the stability of cement and mafic rocks under acidic conditions has not been thoroughly investigated.
INTERNATIONAL JOURNAL OF GREENHOUSE GAS CONTROL
(2023)
Article
Construction & Building Technology
Gustave Semugaza, Tommy Mielke, Marianela Escobar Castillo, Anne Zora Gierth, Joo Xian Tam, Stefan Nawrath, Doru. C. C. Lupascu
Summary: This study demonstrates that reactivating Hydrated Cement Powder (HCP) at lower temperatures can reduce energy consumption and CO2 emissions associated with Ordinary Portland Cement (OPC) production. By heating HCP in the range of 400-800 degrees C, optimal strength in regenerated concrete is achieved. X-ray diffraction (XRD), differential scanning calorimetry (DSC), and thermogravimetry (TG) analyze the crystalline phase transitions, while scanning electron microscopy (SEM) shows the microstructure evolution. Using OPC CEM I 52.5R, 600 degrees C is identified as the optimum heating temperature. Thermally treated HCP can partially replace cement in mortar, achieving similar mechanical strength values.
MATERIALS AND STRUCTURES
(2023)
Article
Construction & Building Technology
Rongjin Cai, Zushi Tian, Hailong Ye, Zhen He, Shengwen Tang
Summary: The pore structure parameters of MHPC blended with metakaolin were studied using an innovative impedance approach, showing that porosity increases with hydration time due to the dissolution of cement and metakaolin grains. The maximal porosities and saturation states of MHPC-metakaolin blended pastes occur concurrently due to the dissolution behavior of cement grains, with the optimal metakaolin incorporation at the 10% replacement ratio for pore structure refinement of blended cement pastes.
CEMENT & CONCRETE COMPOSITES
(2021)
Article
Construction & Building Technology
Jin-Ho Bae, Seonhyeok Kim, Issam T. Amr, Joonho Seo, Daeik Jang, Rami Bamagain, Bandar A. Fadhel, Emad Abu-Aisheh, H. K. Lee
Summary: This study investigated the evaluation of physicochemical properties and environmental impact of Portland cement/metakaolin bricks exposed to humid or CO2 curing condition. The results showed that the CO2 uptake of the CO2-cured paste samples increased with the incorporation of metakaolin. Carbon footprint assessment revealed that the final CO2 emission of the bricks and the corresponding environmental impact can be reduced as the metakaolin dosage is increased.
JOURNAL OF BUILDING ENGINEERING
(2022)
Article
Construction & Building Technology
Suhui Zhang, Qiuyi Li, Qiang Yuan, Shangfu Yang, Xiaodi Dai
Summary: This paper investigated the bonding performance between magnesium phosphate cement concrete (MPC) and ordinary portland cement concrete (OPC) with different roughness. The results showed a positive correlation between roughness and bonding performance, with the bonding interface categorized into two forms: MPC paste bonding to OPC paste, and MPC paste bonding to the aggregate.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
