Article
Construction & Building Technology
Neusa Ap. Munhak Beltrame, Roberto Luiz Dias, Franky Bruno Witzke, Ronaldo A. Medeiros-Junior
Summary: This study evaluated the effect of carbonation curing on the physical, mechanical, and microstructural properties of metakaolin-based geopolymer concrete. The results showed that carbonation curing did not affect compressive strength but improved pore structure and reduced water absorption.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Chemistry, Physical
Qiang Li, Shikun Chen, Yajun Zhang, Yunjin Hu, Quanlin Wang, Quan Zhou, Yongmao Yan, Yi Liu, Dongming Yan
Summary: This paper investigates the preparation and strength performance of a high-strength metakaolin-based geopolymer composite. The results show that heat curing can accelerate the early strength development of the material, but prolonged high-temperature curing can reduce its mechanical strength.
Article
Construction & Building Technology
Dongdong Ma, Wenpu Zhang, Xinpeng Wang, Rongrong Zhang, Zhiwei Zhou, Yi Yang, Yuhang Shi
Summary: Due to increased human activities, construction and maintenance projects in cold regions are facing issues related to cement soil materials. This study systematically investigates the effects of curing temperature and age on the strength and microstructure of cement clay modified by metakaolin (CCM) and cement clay modified by metakaolin and basalt fiber (CCMB). The results show that negative curing temperature increases strain and reduces the decline rate of stress-strain curves. Positive curing temperature and age contribute to increased strength, while the incorporation of basalt fiber has opposite effects on the properties of CCMB specimens at different curing temperatures. Negative curing temperature also inhibits cement hydration and disrupts the bond between basalt fiber and matrix.
JOURNAL OF BUILDING ENGINEERING
(2023)
Article
Construction & Building Technology
Zongyun Mo, Youmin Han, Li Jiang, Jiawei Wang, Xiaojian Gao
Summary: This study investigated the hydration, microstructure, and strength development of UHPC blended with low-energy mineral admixture and cement supplementary material. The results showed that when steam cured at certain temperatures, UHPC had significantly higher compressive strength but lower flexural strength compared to standard cured mixture. The steam curing temperature played a key role in promoting the mineral admixture reaction, while not affecting cement hydration. The use of steam curing regimes resulted in satisfactory mechanical strengths and microstructures for UHPC.
CASE STUDIES IN CONSTRUCTION MATERIALS
(2022)
Article
Construction & Building Technology
Zhi-Hai He, Bin Wang, Hong-Yu Tao, Deng-Deng Wang, Jin-Yan Shi, Ahmed Salah Jamal, Hao-Chen Ding
Summary: This study investigates the effect of low-grade metakaolin (MK) on the volume stability of concrete. The results show that incorporating an appropriate amount of MK can improve the long-term compressive strength and reduce the creep stress of concrete. The addition of MK also increases the content of high-density calcium silicate hydrate (C-S-H) and decreases the contents of pore and Ca(OH)2 phase in the concrete.
JOURNAL OF BUILDING ENGINEERING
(2023)
Article
Construction & Building Technology
Hui Lin, Hui Liu, Yue Li, Xiangming Kong
Summary: The reaction mechanism of phosphoric activated metakaolin was studied by controlling curing temperature and phosphoric acid concentration, resulting in silico-aluminate phosphate samples with high compressive strength. Intermediate products such as P-O-P units were observed during the reaction process, leading to the formation of Al-O-P structure in the final products.
CEMENT AND CONCRETE RESEARCH
(2021)
Article
Materials Science, Multidisciplinary
Alfredo Rondinella, Erika Furlani, Lorenzo Dell'Antone, Elia Marin, Francesco Boschetto, Francesco Sordetti, Alex Lanzutti, Francesco Andreatta, Lorenzo Fedrizzi, Stefano Maschio
Summary: Geopolymers are commonly used in various industries, and this study explores their potential use as coatings for prosthetic devices. The researchers prepared thin and homogeneous geopolymer coatings on a Ti6Al4V alloy and conducted tests to evaluate their adhesion, morphology, chemical characteristics, and antibacterial properties.
JOURNAL OF MATERIALS SCIENCE
(2022)
Article
Construction & Building Technology
Abdulrahman Albidah, Ali S. Alqarni, Husain Abbas, Tarek Almusallam, Yousef Al-Salloum
Summary: Geopolymer or alkali-activated binders are being considered as sustainable alternatives to ordinary Portland cement. This study investigates the behavior of MK-based geopolymer concrete under ambient and elevated temperatures, with varying Na2O/Al2O3 and SiO2/Al2O3 molar ratios affecting the mechanical properties. The residual compressive strength and modulus of elasticity of geopolymer concrete after exposure to elevated temperature show good correlations with experiments.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Fatheali A. Shilar, Sharanabasava V. Ganachari, Veerabhadragouda B. Patil, Kottakkaran Sooppy Nisar
Summary: There has been significant progress in the development of geopolymer as a substitute for Portland cement in the past few decades. It is important to explore the potential applications of geopolymer concrete (GPC) in construction. The study conducted tests on different mixes of metakaolin-based geopolymer with varying alkaline to binder ratios and evaluated their performance. It was found that the A/B ratio of 0.35 resulted in the highest compressive, split tensile, flexural strength, and modulus of elasticity. The strength of geopolymer concrete decreased as the temperature increased. The study also proposed an empirical formula for predicting split tensile strength based on compressive strength values.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Construction & Building Technology
Lifeng Zhang, Rui Ma, Junying Lai, Shaoqin Ruan, Xiaoqian Qian, Dongming Yan, Kuangliang Qian, Su Wang
Summary: This study proposed a new nanocomposite accelerator that can improve the performance of high-strength concrete under low-temperature curing. The experimental results showed that the addition of this accelerator increased the flowability of concrete, shortened the setting time, and had negligible effects on the air content of concrete. Furthermore, the addition of this accelerator significantly enhanced the compressive strength and crack resistance of concrete.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Niloofar Balgourinejad, Mona Haghighifar, Rahmat Madandoust, Shahin Charkhtab
Summary: The main purpose of this experimental research is to investigate the effect of high temperature on microstructural and mechanical properties of lightweight concrete containing Polypropylene fibers (PP) and Metakaolin. The results show that PP fibers can reduce cracking of concrete and make it more durable at high temperatures.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Construction & Building Technology
Abdulrahman S. Albidah
Summary: Considering the environmental concerns and the demand for more sustainable materials, recent research focused on using recycled waste materials and sustainable binders in concrete production. This study investigated the potential of producing geopolymer concrete using metakaolin and reclaimed asphalt pavement (RAP) as aggregate. Experimental tests showed good agreement between proposed models and results, and revealed that replacing natural aggregate with RAP aggregate reduced compressive and flexural strengths. However, the strain at peak strength was increased with higher RAP content.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Construction & Building Technology
Zhi-hai He, Bin Wang, Jin-yan Shi, De-e Liu, Jie Liu, Deng-deng Wang, Yun-jin Hu
Summary: By adding low-grade metakaolin (LMK), the strength and volume stability of concrete can be improved. The addition of 20% LMK can increase the long-term strength of concrete, but higher content of LMK does not have a positive effect on strength improvement. LMK addition can also reduce the drying shrinkage of concrete, and larger sample size can further decrease the shrinkage. The appropriate content of LMK can improve the compactness of microstructure and performance of interfacial transition zone (ITZ).
JOURNAL OF BUILDING ENGINEERING
(2023)
Article
Construction & Building Technology
Yajun Zhang, Shikun Chen, Shengqian Ruan, Wenxin Wang, Quanlin Wang, Dawei Chen, Yi Liu, Dongming Yan
Summary: This study investigates the effects of AC curing and ambient temperature curing on the hardening process of metakaolin-based geopolymer. It identifies two conductive processes in the hardening process: slow process and fast process, which have different effects on pore structure. A thermo-electric model based on Arrhenius equation is proposed and shows good agreement with experimental results. Furthermore, this article provides a new explanation of the coagulation mechanisms underlying the hardening behavior of electrocuring geopolymers.
CEMENT & CONCRETE COMPOSITES
(2023)
Article
Construction & Building Technology
Danbia Lisboa da Costa, Fabiana Pereira Costa, Jucielle Veras Fernandes, Haroldo Cavalcanti Pinto, Juliana de Melo Cartaxo, Gelmires de Araujo Neves, Romualdo Rodrigues Menezes, Alisson Mendes Rodrigues
Summary: This study investigates the effect of a-Al2O3 content, temperature, and curing conditions on the mechanical properties of metakaolin-based geopolymers containing a-Al2O3. The results show that temperature and curing time play a crucial role in the flexural strength (sf), with temperature being a significant factor in all experimental conditions. Inserting a pre-curing step at room temperature for 24 hours favored an increase in sf values. Regardless of the % a-Al2O3, the sf for samples with pre-curing did not vary significantly with the curing time.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Engineering, Multidisciplinary
Jamal Khatib, Ali Jahami, Adel El Kordi, Mohammed Sonebi, Zeinab Malek, Rayan Elchamaa, Sarah Dakkour
Summary: This paper investigates the use of municipal solid waste incineration bottom ash (MSWI-BA) in concrete application, specifically in reinforced concrete (RC) beams. The study shows that replacing 20% of fine aggregates with MSWI-BA can improve the compressive strength, tensile strength, and modulus of elasticity of concrete, but beyond 20% the properties decrease.
JOURNAL OF ENGINEERING DESIGN AND TECHNOLOGY
(2023)
Article
Environmental Sciences
Jamal Khatib, Rawan Ramadan, Hassan Ghanem, Adel ElKordi
Summary: The aim of this study is to investigate the effect of incorporating limestone fine (LF) on the chemical shrinkage of pastes and mortars. The results showed that the long-term chemical shrinkage of pastes increased with the increase in LF content up to 15%, while the chemical shrinkage of mortars decreased beyond a certain LF content. Additionally, the compressive strength of pastes and mortars reached the highest value for mixes containing 10% and 15% LF.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
Article
Green & Sustainable Science & Technology
Firas Barraj, Sarah Mahfouz, Hussein Kassem, Jamal Khatib, Dimitrios Goulias, Adel Elkordi
Summary: Developing sustainable asphalt concrete (AC) mixes using waste glass as filler replacement material is necessary due to the depletion of natural aggregates and high maintenance cost of highway systems. The properties and performance of AC mixtures with different percentages of crushed glass as filler replacement were evaluated. Results showed that the mix containing 25% crushed glass exhibited better resistance to fatigue cracking, but lower rutting resistance compared to conventional hot mix asphalt (HMA). Flow number test and simple performance indicators were used to rank the mechanical performance of the mixtures.
Article
Green & Sustainable Science & Technology
Hassan Ghanem, Safwan Chahal, Jamal Khatib, Adel Elkordi
Summary: The generation of plastic waste is increasing rapidly worldwide, leading to concerns regarding its disposal. Recycling is considered as a viable and attractive option to tackle this issue, as landfill space is limited and incineration releases toxic elements. This study examined the flexural behavior of mortar beams reinforced with recycled plastic mesh. The results showed that adding plastic mesh increased the flexural toughness and ductility of the mortar beams. Numerical simulation and experimental analysis showed a correlation between effective width ratio and ultimate capacity, flexural toughness, and ductility index. The findings suggest that using recycled plastic mesh can enhance the flexural performance of mortar beams, promoting sustainability.
Article
Green & Sustainable Science & Technology
Yassir M. Abbas, Nasir Shafiq, Galal Fares, Montasir Osman, Mohammad Iqbal Khan, Jamal M. Khatib
Summary: The development of sustainable construction methods can be achieved by improving the performance of reinforced concrete elements, resulting in an increase in structural life expectancy. This study focuses on the structural performance of shear-deficient ultrahigh-performance concrete (UHPC) beams and suggests that high-strength fibers can extend structural lifetimes in UHPC applications. Experimental optimization of UHPC mixes resulted in characteristic compressive strengths of 130 +/- 10 MPa and elastic moduli of 8 GPa for plain UHPC and 40 GPa for fiber-reinforced UHPC. The study also investigated the structural behavior of 18 sets of reinforced UHPC beams, varying the overall depth, reinforcement ratio (rho), and shear-span-to-depth ratio (lambda).
Article
Chemistry, Multidisciplinary
Rawan Ramadan, Ali Jahami, Jamal Khatib, Hilal El-Hassan, Adel Elkordi
Summary: The construction industry has shown increasing interest in sustainable materials, driven by the need to reduce environmental impact and improve indoor air quality. Phragmites australis fibers, a renewable and biodegradable material with a low carbon footprint, have gained popularity in construction. This study evaluated the impact of Phragmites australis fibers on reinforced concrete beams. Results showed that while the fibers slightly decreased compressive and tensile strength, they improved split tensile and flexural strength. The mix with 10% glass and 0.5% Phragmites australis fibers exhibited the highest ductility index and deflection in reinforced concrete beams.
APPLIED SCIENCES-BASEL
(2023)
Review
Construction & Building Technology
Yousra Hachem, Mohamad Ezzedine El Dandachy, Jamal M. Khatib
Summary: The paper provides a state-of-the-art review on the properties of the steel-concrete interface (SCI) and its impact on the overall performance of reinforced concrete. It reveals that physical characteristics of concrete and various factors, such as rebar shape and diameter, anchorage length, concrete grade strength, binder type, and aggregate distribution, significantly influence the interface properties and behavior. The transfer properties at the SCI are influenced by steel rebar, crack dimensions, degree of saturation of concrete, and concrete mix design.
Article
Construction & Building Technology
Zeinab Nasser Eddine, Jamal Khatib, Adel El Kordi, Lateef Assi
Summary: This paper investigates the potential of using MSWI-BA to produce eco-friendly pervious concrete pavement in Lebanon. The results show that even with 100% replacement of natural aggregate with MSWI-BA, the engineering properties of pervious concrete still meet the standard requirements.
INTERNATIONAL JOURNAL OF PAVEMENT RESEARCH AND TECHNOLOGY
(2023)
Article
Engineering, Civil
Ali Hatoum, Jamal Khatib, Adel Elkordi
Summary: This study compares the mechanistic empirical (NCHRP1-37A) design method with the empirical 1993 AASHTO design method. Flexible pavement sections from different regions in the United States with varying climatic conditions were selected for the study. Data from FHWA's Long-Term Pavement Performance (LTPP) program were used to define and characterize the pavement structure. The results showed significant differences in predicted pavement performance between the two design approaches.
TRANSPORTATION INFRASTRUCTURE GEOTECHNOLOGY
(2023)
Article
Construction & Building Technology
Abderrazak Barkat, Said Kenai, Belkasem Menadi, El-Hadj Kadri, Jamal Khatib
Summary: This paper investigates the relationship between the fresh properties of local-metakaolin based self-compacting concrete (SCC) and the spreading of its mortar portion, finding a good correlation between them. The substitution of cement with metakaolin does not affect this correlation. Choosing the appropriate mortar flow can achieve the required rheological properties of SCC.
Article
Construction & Building Technology
Ali Jahami, Hussein Younes, Jamal Khatib
Summary: This research investigated the effects of integrating steel dust as a partial substitute for cement in reinforced concrete beams. The findings showed that the workability of the concrete mixture decreased as the proportion of steel dust increased, impacting the elasticity modulus. Compressive strength increased at a 10% replacement of cement, but declined with higher levels of substitution. Adjusted equations for split tensile and flexural strength were formulated with the inclusion of steel dust. Ductility increased with 10% steel dust, but decreased along with the maximum load-bearing capacity at a 30% inclusion level. Prudence is needed when considering the use of steel dust as a cement substitute, especially approaching or exceeding the 10% replacement threshold. Further comprehensive research is necessary to fully understand its implications and susceptibility to corrosion concerns.
Article
Construction & Building Technology
Arun Kumar, Rahul Kumar Meena, Ritu Raj, Mohammad Iqbal Khan, Jamal M. Khatib
Summary: This study discusses the effect of wind on the irregular cross-section shape of tall buildings and is conducted numerically. The research findings show that the maximum critical suction on the recessed faces of the model occurs at a wind incident angle of 105 degrees.
Article
Construction & Building Technology
Bengin M. A. Herki, Jamal M. Khatib, Muhammad N. Hamadamin, Fakhir A. Kareem
Summary: This study aimed to investigate the properties of self-curing concrete by adding Polyethylene glycol-400 (PEG-400) as one of the concrete mix constituents in order to save water required for curing.
Article
Construction & Building Technology
Herda Yati Binti Katman, Wong Jee Khai, Naraindas Bheel, Mehmet Serkan Kirgiz, Aneel Kumar, Jamal Khatib, Omrane Benjeddou
Summary: This study explores the substitution of cement in concrete with wheat straw ash (WSA) as an environmentally friendly alternative. The results showed that substituting 10% of PC with WSA resulted in the highest concrete strength, while substituting 20% of PC with WSA reduced the mechanical properties and permeability of concrete.
Article
Construction & Building Technology
Firas Barraj, Jamal Khatib, Alberte Castro, Adel Elkordi
Summary: Newer technologies such as warm mix asphalt and reclaimed asphalt pavement have been considered as appropriate solutions for sustainable goals in the highway sector. However, both technologies have some shortcomings. This study investigates a combined warm mix asphalt-reclaimed asphalt pavement technology to overcome these shortcomings and improve the cracking resistance of reclaimed asphalt pavement mixtures.
