Transformation of Construction Cement to a Self-Healing Hybrid Binder

Müller, Wernér E.G.; Tolba, Emad; Wang, Shunfeng; Li, Qiang; Neufurth, Meik; Ackermann, Maximilian; Muñoz‐Espí, Rafael; Schröder, Heinz C.; Wang, Xiaohong

doi:10.3390/ijms20122948

Cited by 3 publications

(11 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…During the aging process of the cement, the bacteria that co-exist with the "ACCP10" particles in the cement, with their alkaline phosphatase on their cell surfaces, dissolve the polymer polyP and allow a crystallization of Ca-carbonate to calcite [12]. The bacteria will initiate first, the enzymatic dissolution of the polyP in the particles and second, simultaneously, the formation of a polyP coacervate around the amorphous Ca-carbonate, as disclosed recently [13].…”

Section: Discussionmentioning

confidence: 92%

“…The "ACCP10" particles contain within their Ca-carbonate deposits also polyP, which most likely prevents a fast transformation of the amorphous phase of Ca-carbonate into a crystalline phase. During the aging process of the cement, the bacteria that co-exist with the "ACCP10" particles in the cement, with their alkaline phosphatase on their cell surfaces, dissolve the polymer polyP and allow a crystallization of Ca-carbonate to calcite [12]. The bacteria will initiate first, the enzymatic dissolution of the polyP in the particles and second, simultaneously, the formation of a polyP Figure 13.…”

Section: Discussionmentioning

confidence: 99%

“…The breaking loads of the cement samples were determined with a 3-point bending system (5940 Series system; Instron, Norwood, MA), following a previously described procedure [12]. The standardized spherical loading head (diameter of 18 mm) and defined cement samples (83 mm in length × 30 mm width × 10 mm height) were used.…”

Section: Mechanical Toughness: 3-point Bend Testingmentioning

confidence: 99%

“…Following a previously described protocol [12], the sample "hCEM•ACCP10" was selected, which were aged for 10 days. Then microcracks were placed into the cement blocks by five shock freeze-warming cycles with liquid nitrogen (−196 • C)-heating at 80 • C. The resulting diameters of the cracks were ≈15 to ≈66 µm (48 ± 14 µm; 25 determinations).…”

Section: Microcrack Formation and Self-healing Analysismentioning

confidence: 99%

See 3 more Smart Citations

Self-Healing Properties of Bioinspired Amorphous CaCO3/Polyphosphate-Supplemented Cement

Tolba

Wang

et al. 2020

Molecules

Self Cite

View full text Add to dashboard Cite

There is a strong interest in cement additives that are able to prevent or mitigate the adverse effects of cracks in concrete that cause corrosion of the reinforcement. Inorganic polyphosphate (polyP), a natural polymer that is synthesized by bacteria, even those on cement/concrete, can increase the resistance of concrete to progressive damage from micro-cracking. Here we use a novel bioinspired strategy based on polyP-stabilized amorphous calcium carbonate (ACC) to give this material self-healing properties. Portland cement was supplemented with ACC nanoparticles which were stabilized with 10% (w/w) Na–polyP. Embedding these particles in the hydrated cement resulted in the formation of calcite crystals after a hardening time of 10 days, which were not seen in controls, indicating that the particles dissolve and then transform into calcite. While there was no significant repair in the controls without ACC, almost complete closure of the cracks was observed after a 10 days healing period in the ACC-supplemented samples. Nanoindentation measurements on the self-healed crack surfaces showed a similar or slightly higher elasticity at a lower hardness compared to non-cracked surfaces. Our results demonstrate that bioinspired approaches, like the use of polyP-stabilized ACC shown here, can significantly improve the repair capacity of Portland cement.

show abstract

Section: Discussionmentioning

confidence: 92%

Section: Discussionmentioning

confidence: 99%

Section: Mechanical Toughness: 3-point Bend Testingmentioning

confidence: 99%

Section: Microcrack Formation and Self-healing Analysismentioning

confidence: 99%

See 2 more Smart Citations

Self-Healing Properties of Bioinspired Amorphous CaCO3/Polyphosphate-Supplemented Cement

Tolba

Wang

et al. 2020

Molecules

Self Cite

View full text Add to dashboard Cite

show abstract

“…[18] In turn, we outlined in a previous study that polyP is a new cornerstone for the improvement of cement formulation both for biomedical applications [10] and as a construction material. [19] In addition to polyP as a major building block and energy supplier required for the stabilization of cement both for constructions and bone, Ca 2+ -salts like Ca-carbonate are of great importance. It is well established that limestone, formed predominantly of calcite, is a crucial additive for Portland cements amounting to about 5 wt% of the cement.…”

Section: Introductionmentioning

confidence: 99%

Amorphous Polyphosphate and Ca‐Carbonate Nanoparticles Improve the Self‐Healing Properties of both Technical and Medical Cements

Tolba

Wang

et al. 2020

Biotechnology Journal

Self Cite

View full text Add to dashboard Cite

Cement is used both as a construction material and for medical applications. Previously, it has been shown that the physiological polymer inorganic polyphosphate (polyP) is morphogenetically active in regeneration of skin, bone, and cartilage. The present study investigates the question if this polymer is also a suitable additive to improve the self-healing capacity not only of construction cement but also of inorganic bone void fillers. For the application in the cement, two different polyP-based amorphous nanoparticles (NP) are prepared, amorphous Ca-polyP NP and amorphous Ca-carbonate (ACC) NP. The particles are integrated into poly(methyl methacrylate) in a concentration ratio of 1:10. This material applied onto Portland cement blocks either by brush application or by blow spinning strongly accelerates the self-healing property of the cement after a 10 day incubation period. Most likely, this process depends on bacteria and their membrane-associated alkaline phosphatase, resulting in the formation of calcite from ACC. In a second approach, polyP is integrated into a calcium-silicate-based cement used in reconstitutive medicine. Subsequently, the cement becomes softer and more elastic. The data show that bioinspired polyP/ACC NP are suitable additives to improve the self-healing of construction cement and to biologize bone cement.

show abstract

Problems of the safe use of modern cement materials in the practice of drinking water supply

Алексеева

Савостикова

2023

Hygiene and Sanitation

View full text Add to dashboard Cite

Introduction. Recently, there have been increasing changes in the technology of preparation of cement mixtures and concrete, the use of new components in their composition, since traditional materials are not quite suitable for the construction of hydraulic structures, including the internal coating of pipes and drinking water tanks. However, in addition to improving the characteristics of cement mixtures, additives can have a negative impact on the environment and human health by leaching out of cement into drinking water. The definition of only the main components specified in the “Universal sanitary-epidemiological and hygienic requirements for goods subject to sanitary-epidemiological supervision (control)” (hereinafter - the Universal Requirements) does not provide complete information about the chemical safety of cement materials during the hygienic assessment. Materials and methods. There were studied eleven samples of cement mixtures from various manufacturers repaired of reinforced concrete products and structures of general and special purpose, including those in contact with drinking water, and used for the sanitation of the internal surfaces of steel pipelines (including hot water supply systems) and repair and restoration work. The evaluation of samples was carried out taking into account Universal requirements, and indicators that are not mandatory for the evaluation of these materials were investigated. Results. Hygienic assessment of cement mixtures showed lithium to be detected in some extracts in concentrations from 20 mg/L to 0.18 mg/L, which is 666 times higher than its maximum permissible concentration - 0.03 mg/L. Also, two samples showed a slight excess of the permissible chromium concentration - 0.065 mg/L and 0.09 mg/L (MPC < 0.05). Iron and zinc in insignificant concentrations were found in aqueous extracts; in one of the samples a 2-fold excess of the manganese concentration was observed. One water extract contains silicates at a concentration of 34.24 mg/L, which exceeds their permissible levels in drinking water. The analysis also identified a number of organic compounds related to oxygen-containing compounds (alcohols, phenol derivatives, ketones, esters, phthalates), for most of which no MPC has been established. Limitations. The study was carried out on eleven samples of cement mixtures under standard conditions: infusion in model media for 30 days at room temperature in the ratio: 1 cm2 of the sample surface to 1 cm3 of water. Sampling was carried out on the Days 1, 3, 5, 10, 20 and 30 of research, without changing the test water. It is necessary to conduct similar studies under experimental conditions close to the operating conditions of these materials. Conclusion. Assessing the efficiency of migration from cement-bound materials, it is necessary to take into account their capillary-porous structure on the one hand and the ability to improve the coating properties over time by converting calcium hydroxide present in freshly applied cladding into denser calcium bicarbonate. The migration of chemicals from cement-bound material is to be evaluated by taking into account the specific conditions of their use in the practice of drinking water supply, and the assessment of the additives introduced should be carried out on test cement samples, since it is impossible to theoretically calculate the migration rate of the components from the finished material.

show abstract

Transformation of Construction Cement to a Self-Healing Hybrid Binder

Cited by 3 publications

References 51 publications

Self-Healing Properties of Bioinspired Amorphous CaCO3/Polyphosphate-Supplemented Cement

Self-Healing Properties of Bioinspired Amorphous CaCO3/Polyphosphate-Supplemented Cement

Amorphous Polyphosphate and Ca‐Carbonate Nanoparticles Improve the Self‐Healing Properties of both Technical and Medical Cements

Problems of the safe use of modern cement materials in the practice of drinking water supply

Contact Info

Product

Resources

About