Improvement in properties of concrete with modified RCA by microbial induced carbonate precipitation

Zhao, Yongjun; Peng, Ligang; Zeng, Weilai; Poon, Chi Sun; Lü, Zhenmei

doi:10.1016/j.cemconcomp.2021.104251

Cited by 63 publications

(11 citation statements)

References 51 publications

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“…In the first, the fissure was generated in the old NCA and in the second it is in the old mortar, both present in the RCA, the new NCA does not present damage. There are 3 different ITZs in the concrete: new NCA -new mortar, old NCA -old mortar and old mortar -new mortar [20], generated due to the superficial absorption of the aggregate water, which absorbs the water present in the mortar during the process of manufacturing, generating an area with poor hydration and giving rise to the ITZ [21], this has a marked influence on the different properties of water flow and ions in the mass of the concrete by having permeability properties superior to the rest of the mass of the concrete. Resistance to compression and its reduction with increments of r is shown in Figure 6, being an inverse linear relation.…”

Section: Interfacial Transition Zonementioning

confidence: 99%

Estudio de permeabilidad y propiedades mecánicas de concreto elaborado con sustituciones de grueso reciclado. agregado: alternativa sostenible

Rodriguez Rodriguez,

Pellegrini Cervantes,

Corral Higuera

et al. 2023

Lat. Ame. Jour. App. Eng.

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The use of recycled aggregates for the production of concrete is increasingly frequent, contributing to the preservation of the environment by reducing the consumption of natural aggregates. Unfortunately, the properties of concrete manufactured with recycled aggregate differ from those of conventional concrete, being the entrance of water and aggressive ions a determining factor in the durability of structures, thus making it important the study of their mechanical and permeable properties. In this work the resistance to compression and the permeability properties of concrete manufactured with the replacement of natural coarse aggregate. Therefore, adding 25% recycled coarse aggregate guarantees a performance similar to conventional concrete without compromising the durability of civil works, making the concrete manufactured with recycled coarse aggregate a viable alternative as a sustainable material to use in the construction industry.

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Section: Interfacial Transition Zonementioning

confidence: 99%

Estudio de permeabilidad y propiedades mecánicas de concreto elaborado con sustituciones de grueso reciclado. agregado: alternativa sostenible

Rodriguez Rodriguez,

Pellegrini Cervantes,

Corral Higuera

et al. 2023

Lat. Ame. Jour. App. Eng.

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“…Among these methods, impregnation is the most common, using sodium silicate solutions [19,24,25], lithium silicate [26], PVA [25,27], silane [24,25], silica fume and nano-silica [28,29], cement slurry [30] and cement with silica fume [19]. The possibility of sealing recycled aggregate by depositing calcium carbonate in the pores of old mortar is also being investigated [31,32], as well as improving its properties by ultrasonic washing [28]. The effects of combining these methods from both groups, i.e., first removing the old mortar and then improving the pre-treated aggregate, are also being investigated [33].…”

Section: Introductionmentioning

confidence: 99%

Influence of Citric Acid-Assisted Impregnation of Recycled Aggregate on the Properties of the Resultant Concrete

2023

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The paper presents the results of tests on concrete with recycled aggregate impregnated with the use of citric acid. Impregnation was carried out in two stages, with a suspension of calcium hydroxide in water (so-called milk of lime) or diluted water glass used as the second impregnant. The mechanical properties of the concrete were carried out: compressive strength, tensile strength and resistance to cyclic freezing. In addition, concrete durability parameters such as water absorption, sorptivity and torrent air permeability were investigated. The tests showed that this type of impregnation did not improve most of the parameters of concrete with impregnated recycled aggregate. The mechanical parameters after 28 days were significantly lower compared to the reference concrete, although after a longer curing period, these differences decreased significantly for some series. The durability parameters of the concrete with impregnated recycled aggregate also deteriorated compared to the reference concrete with the exception of air permeability. The results of the tests carried out indicate that impregnation using water glass in combination with citric acid gives the best results in most cases and that the order in which the impregnation solutions are applied is very important. Tests also showed that the effectiveness of impregnation is very much influenced by the value of the w/c ratio.

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“…Despite the potential of using aeolian sands as a cost-effective building material, their low shear strength and lack of viscosity make them unsuitable for direct use in building materials [20][21][22]. While Microbially Induced Calcite Precipitation (MICP) holds the potential to transform these loose sands into viable building materials [4,23], the method has its shortcomings. In particular, the uneven distribution of precipitated calcite and insufficient mechanical strength in the consolidated sand pose significant challenges.…”

Section: Introductionmentioning

confidence: 99%

Polypeptide additives for improving the performance of microbially induced calcite precipitation (MICP) sand consolidation

Wang,

Chen,

Song

et al. 2023

Preprint

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Recognizing the limitations of Microbially Induced Calcite Precipitation (MICP) for sand consolidation, particularly the insufficient mechanical strength and the uneven distribution of precipitated calcite, our research takes an innovative approach. For the first time, we compare the potential of various polypeptide additives, including polylysine, polyaspartic acid, and polyglutamic acid, to enhance the MICP process. The optimal polypeptide was determined as polylysine, which could increase sand samples’ unconfined compressive strength (UCS) by 35.03% after MICP treatment. The optimal polylysine concentration is 100 mg/L, and the cementing liquid cost increased by only 3%. When the polylysine concentration exceeded 100 mg/L, the UCS of sand-solidified samples decreased. Environmental scanning electron microscope (ESEM) images showed that calcium carbonate and sand were bonded more tightly with polylysine added, and the distribution of calcium carbonate was uniform in the sand samples treated by MICP. X-ray diffractometer (XRD) showed calcium carbonate’s crystal form is calcite. This research signifies a crucial step forward in optimizing MICP for sand consolidation, potentially transforming applications in construction, geotechnical engineering, and environmental remediation.

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Improvement in properties of concrete with modified RCA by microbial induced carbonate precipitation

Cited by 63 publications

References 51 publications

Estudio de permeabilidad y propiedades mecánicas de concreto elaborado con sustituciones de grueso reciclado. agregado: alternativa sostenible

Estudio de permeabilidad y propiedades mecánicas de concreto elaborado con sustituciones de grueso reciclado. agregado: alternativa sostenible

Influence of Citric Acid-Assisted Impregnation of Recycled Aggregate on the Properties of the Resultant Concrete

Polypeptide additives for improving the performance of microbially induced calcite precipitation (MICP) sand consolidation

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