Studying the influence of metakaolin on self-healing processes in the contact-zone structure of concretes based on the alkali-activated Portland cement

Kovalchuk, Oleksandr; Gelevera, Oleksandr; Ivanychko, Vasyl

doi:10.15587/1729-4061.2019.181501

Cited by 3 publications

(1 citation statement)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While the reaction of the Al 2 O 3 site with gypsum (CaSO 2 •2H 2 O) in aqueous solutions will produce an ettringite phase, which contributes to the initial strength of the concrete structure [8,12]. The paper [13] also shows that the addition of 15 % metakaolin to the cement composition possibly prevents destructive processes in concrete exposed in a high alkali content environment.…”

Section: The Aim and Objectives Of The Studymentioning

confidence: 99%

Structural and microscopy characterization of an alternative low-energy binder containing Ca(OH)2 as an alkaline activator

Ramelan

Nugroho

Indriati

et al. 2021

EEJET

View full text Add to dashboard Cite

The development of potential alternative binders to Portland cement is still becoming a global challenge in housing and infrastructure aspects. That is because cement and concrete become the major materials needed in building constructions. The Ordinary Portland cement can form a solid and hard mass when mixed with water with a certain ratio. This is due to the formation of ettringite and calcium silicate hydrate (CSH) phases that contribute to the strength of the hydrated products about 33–53 MPa. However, the manufacturing temperature of Portland cement can reach up to 1,500 °C in producing clinker. In order to lower the energy consumption and production cost, scientists were trying to utilize pozzolanic materials. The research of pozzolanic materials as alkali-activated cement, such as soil cement or geopolymer cement, is also still conducted. Hence, a better understanding of pozzolanic reaction and its hydration products is needed. In this work, the hydration products of low-energy binders composed of Ca(OH)2-SiO2 and Ca(OH)2-metakaolin-gypsum mixtures were studied. The hydrated products of 41 wt. % Ca(OH)2 – 41 wt. % metakaolin – 18 wt. % gypsum mixtures followed by water immersion curing at 50 °C for 28 days undergone a pozzolanic reaction. XRD characterization showed that the hydrated product is mainly composed of ettringite (60.0 %) and crystalline-CSH (23.4 %). The diffractograms obtained have shown a specific hump indicating the presence of amorphous phases besides the crystalline. To confirm the presence of the non-crystalline or amorphous phases of the hydrated products, a polarizing optical microscope (OM) using a crossed Nicols method was used. The characterization of the phases is the novelty of the present research. The ettringite, crystalline CSH and the amorphous phases act as a strong binder that consequently contribute to its average maximum compressive strength of 22.17 MPa.

show abstract

Section: The Aim and Objectives Of The Studymentioning

confidence: 99%

Structural and microscopy characterization of an alternative low-energy binder containing Ca(OH)2 as an alkaline activator

Ramelan

Nugroho

Indriati

et al. 2021

EEJET

View full text Add to dashboard Cite

show abstract

Study of influence of alkaline component type on pH value and properties of alkali activated concretes containing basalt rock

Kovalchuk

Zozulynets

2021

E3S Web Conf.

Self Cite

View full text Add to dashboard Cite

The paper discusses the questions of alkalinity changes in alkali activated cement-based materials at different stages of hardening. It was shown that use of alkali activated cement with dry alkaline component (“all-in-one system”) in the presence of basalt rock leads to the immediate decrease of pH value and strength drop of the material. On the other hand, using alkaline component in the form of alkaline solution provides almost normal hardening of systems. Taking into account obtained results a methodology of changes in concrete mix design was proposed. In general, for different cement systems under study pH value varies from 8.5 to 12 reflecting on the materials structure formation processes and strength gain. Shrinkage of the systems was within the ranges 0.3…0.6 mm/m at 28 days age and 0.3…0.5 mm/m for different systems. Absence of expansion witnesses about compensation of ASR results and normal structure developments processes in the material comparing to OPC.

show abstract

The role of kaolinite clay in the evolution of the structure and properties of slag-alkali cements

Krivenko,

Gelevera,

Rogozina

2023

World Multidisciplinary Civil Engineering-Architecture-Urban Planning Symposium Wmcaus 2022

View full text Add to dashboard Cite

Studying the influence of metakaolin on self-healing processes in the contact-zone structure of concretes based on the alkali-activated Portland cement

Cited by 3 publications

References 26 publications

Structural and microscopy characterization of an alternative low-energy binder containing Ca(OH)2 as an alkaline activator

Structural and microscopy characterization of an alternative low-energy binder containing Ca(OH)2 as an alkaline activator

Study of influence of alkaline component type on pH value and properties of alkali activated concretes containing basalt rock

The role of kaolinite clay in the evolution of the structure and properties of slag-alkali cements

Contact Info

Product

Resources

About