Cement paste is the main binding component in concrete and thus its fundamental properties are of great significance for understanding the fracture behaviour as well as the ageing process of concrete. One major aim of this paper is to characterize the micromechanical properties of cement paste with the aid of a nanoindenter. Besides, this paper also presents a preliminary study on the fatigue behaviour of cement paste at the micrometer level. Miniaturized cantilever beams made of cement paste with different water/cement ratios were statically and cyclically loaded. The micromechanical properties of cement paste were determined based on the measured load-displacement curves. The evolution of fatigue damage was evaluated in terms of the residual displacement, strength, and elastic modulus. The results show that the developed test procedure in this work is able to produce reliable micromechanical properties of cement paste. In addition, little damage was observed in the cantilever beams under the applied stress level of 50% to 70% for 1000 loading cycles. This work may shed some light on studying the fatigue behaviour of concrete in a multiscale manner.
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http://dx.doi.org/10.3390/mi9120630 | DOI Listing |
J Indian Soc Pedod Prev Dent
October 2024
Department of Pediatric and Preventive Dentistry, Subharti Dental College and Hospital, Swami Vivekanand Subharti University, Meerut, Uttar Pradesh, India.
Background And Aim: This study aims to evaluate the efficacy of different endodontic irrigants employed in the lesion sterilization and tissue repair (LSTR) technique.
Methods: Forty children aged 4-8 years having at least one primary molar with irreversible pulpitis/pulpal necrosis indicated for pulpectomy were included. Participants were randomly divided into three test groups (Group A, B, and C) and one control group (Group D).
Materials (Basel)
January 2025
College of Hydraulic and Civil Engineering, Xinjiang Agricultural University, Urumqi 830052, China.
Hydraulic structures are frequently subjected to soft-water or acidic environments, necessitating serious consideration of the long-term effects of calcium leaching on the durability of concrete structures. Three types of common Portland cement (ordinary Portland cement, moderate-heat cement, and low-heat cement) paste samples widely applied to hydraulic concrete were immersed in a 6 mol/L NHCl solution to simulate accelerated calcium leaching behavior. The mass loss, porosity, leaching depth, compressive strength, and Ca/Si ratio of the three types of pastes were measured at different immersion stages (0, 14, 28, 56, 91, 140, and 180 days).
View Article and Find Full Text PDFMaterials (Basel)
January 2025
Gansu Industry Technology Center of Transportation Construction Materials Research and Application, Lanzhou Jiaotong University, Lanzhou 730070, China.
In order to study the effect of the crushing process on the fine separation of reclaimed asphalt pavement (RAP) and the mechanical properties of cement-stabilised aggregate mixed with RAP, four crushing processes, namely small mesh hammer crushing, hammer crushing, jaw crushing, and double roller crushing, were used to separate the aggregate from asphalt in RAP materials. The effect of crushing on the grading characteristics and agglomeration condition of RAP material was investigated. RAP cement-stabilised aggregates were prepared and analysed for their mechanical properties and micro-morphology using RAP materials obtained from fine separation.
View Article and Find Full Text PDFMaterials (Basel)
December 2024
College of Water Conservancy and Civil Engineering, Inner Mongolia Agricultural University, Hohhot 010018, China.
Gasification slag is the solid waste produced in the process of coal gasification. China produces approximately 30 million tons of gasification slag every year, which urgently needs to be recycled in an efficient and sustainable way. This paper discusses the feasibility of using gasification slag as a supplementary cementitious material (SCM).
View Article and Find Full Text PDFJ Esthet Restor Dent
January 2025
Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand.
Objective: To conduct a systematic review on the masking ability of subtractively and additively manufactured dental ceramics.
Materials And Methods: The study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The electronic search was carried out through MEDLINE, Scopus, and Website of Science databases with a date restriction being from 2001 onwards.
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