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Investigation of Mechanical, Physical and Durability Properties of Metakaolin-Based Geopolymer

Ibrahim Wan Mastura Wan, Ibrahim Masdiyana, Azis Mohammad Zaki Bin, Abdullah Mohd Mustafa Al Bakri, Sauffi Ahmad Syauqi, Romisuhani Ahmad, Adnan Suraya Hani

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 3

1069--1075

EN

Due to their potential to lower CO2 emissions linked with the cement and concrete industries, geopolymer binders are a desirable alternative for Portland cement binders. However, if they are to become a viable alternative to conventional Portland cement materials, their resilience in harsh conditions has to be further investigated. This paper presented mechanical and short-term durability properties of metakaolin based geopolymer concrete at sulphuric acid (H2SO4) solutions exposed with the concentrations of 2%, 3%, 4% and 5% for 14 days. (0%) or unexposed sample also prepared as referral and comparison. The geopolymer concretes were synthesized using an alkali activation of sodium hydroxide (NaOH) and sodium silicate (Na2SiO3). The main objective of the study was to examine the durability and deterioration mechanism parameters like different acid percentages, changes in weight, compressive strength, density and water absorption. Morphology analysis also performed in this study. The results indicated that metakaolin geopolymer experienced some strength deterioration with increasing sulphuric concentration solutions which are from 32.58 MPa, 20.67 MPa and 4.25 MPa at unexposed (0%), 2% and 5% sulphuric acid immersion respectively. Furthermore, change in weight or mass loss and water absorption after the chemical attack resulted directly proportional to sulphuric acid concentration due to increment of crack on the sample. Among that, the metakaolin geopolymer submerged in 2% acid gives the optimum results in terms of durability, mechanical and physical qualities.

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Ocena przyczyn i stopnia zniszczenia nawodnych podpór mostu hydraulicznego odpopielania

Błaszczyński Tomasz, Łowińska-Kluge Aldona

Przegląd Budowlany

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2020

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R. 91, nr 11

18--23

PL

W przedstawianym artykule opisano przypadek uszkodzeń betonu w nawodnych podporach mostu hydraulicznego odpopielania w jednej z elektrowni. Dokonanie oceny przyczyn zniszczenia betonu, jak i określenie możliwości wystąpienia w nim zjawisk korozyjnych, a więc w konsekwencji prognozowania trwałości obiektu budowlanego oraz wybór, na tej podstawie, właściwej procedury naprawczo-renowacyjnej wymagało przeprowadzenia szeregu niezbędnych badań i analiz. I tak, w omawianym przypadku, przeprowadzono kompleksowe badania na obiekcie i badania na próbkach betonu wyciętych, w postaci odwiertów rdzeniowych, z uszkodzonej konstrukcji (m.in. makroskopowe, mikroskopowe SEM, XRD, DTA, analizy chemiczne). W oparciu o te badania ustalono rodzaje korozji odpowiedzialne za analizowane zniszczenia.

EN

The article describes a case of concrete damage in waterway supports of a hydraulic bridge for ash removal in one of power plants. Assessment of concrete destruction causes, as well as determination of the possibility of corrosion occurring in the concrete, and therefore, as a consequence of forecasting the durability of the construction facility and selection of appropriate repair and renovation procedure, required a number of necessary tests and analyses. In the discussed case, comprehensive tests on the facility and on concrete samples, cut out of the damaged construction in the form of cored boreholes (including macroscopic, microscopic, SEM, XRD, DTA tests and chemical analyses) were carried out. Based on these tests, the types of corrosion responsible for the analysed damage were determined.

3

Chemical attack in free boundary domains

Clain S.

Journal of Applied Analysis

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1999

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Vol. 5, nr 1

35-58

EN

This paper presents a mathematical model for a chemical process used to machine cristal as glass or silica. A short physical description is presented from which we draw the mathematical model. We obtain a coupled parabolic equations system on a free boundary domain with a non-linear condition on the boundary. The existence and the uniqueness is proved in the one-dimensional case.