Effects of Carbonated Recycled Concrete Aggregate on Mechanical Properties of Concrete and Micro-Properties of Interfacial Transition Zone

Wu, Jun

doi:10.13168/cs.2022.0006

Cited by 6 publications

(4 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…6). This indicates that when the SP content continued to increase after exceeding the optimal value, although the optimization effect of SP on the larger pores tended to be stable, it increased the total number of small pores; this is consistent with the reports (Wu et al 2017;Liu et al 2011). In addition, it is also believed that the increase in the number of this micro pores did not affect the mechanical properties and durability of the concrete.…”

Section: Pore Structuresupporting

confidence: 90%

Experimental Studies to Investigate Efficacies of Granite Porphyry Powder as Homologous Manufactured Sand Substitute

Liu

Zhu

et al. 2023

ACT

View full text Add to dashboard Cite

Stone powder and others waste powder causes serious harm to the environment, society, ecosystem and human well-being, applying it to concrete is a path of green and effective. In this study, a series of tests was carried out on manufactured sand concrete with different granite porphyry powder contents. The results showed that when the stone powder content was lower than 8%, the cracking resistance, compressive strength, chloride ion permeability resistance, and sulfate attack resistance of the concrete were significantly improved with an increase in the stone powder content. Although the early shrinkage rate of the concrete also increased with the increase in the stone powder content, the increase rate was slow. At the microstructure level, an appropriate amount of stone powder exhibited the ‶filling effect" and "nucleation effect," which were conducive to the improvement of the concrete mechanical properties and durability. However, with an increase in the stone powder content, the early shrinkage of the concrete increased sharply when the stone powder content exceeded 8%, and the crack resistance, compressive strength, and chloride ion permeability resistance of the concrete decreased. At this time, the stone powder had a "diversified effect" on the microstructure of the concrete, and the existence of a large amount of stone powder was not conducive to the development of certain properties of the concrete. It is feasible to prepare concrete by replacing manufactured sand with an appropriate amount of stone powder and others waste powder, which can not only improve the performance of concrete, but also save cost, energy, avoid manpower and material consumption in waste powder disposal. The research conclusion shows that the allowable value of the stone powder content can be appropriately increased according to the actual application in concrete, which is an efficient, green disposal path for stone powder and other waste powder.

show abstract

Section: Pore Structuresupporting

confidence: 90%

Experimental Studies to Investigate Efficacies of Granite Porphyry Powder as Homologous Manufactured Sand Substitute

Liu

Zhu

et al. 2023

ACT

View full text Add to dashboard Cite

show abstract

“…It was known that there were a large number of different pore diameter micropores with nonuniform distribution inside the concrete, and different pore size micropores had different effects on concrete performances. For example, micropores with less than 20 nm diameter are not harmful to concrete performances, micropores with 20–100 nm diameter have a little effect on concrete performances and micropores with more than 100 nm diameter are considered harmful to concrete performances . The MIP test was used in order to explain the effect of the SF on the pore size of matrix in CPCGA.…”

Section: Resultsmentioning

confidence: 99%

“…For example, micropores with less than 20 nm diameter are not harmful to concrete performances, micropores with 20−100 nm diameter have a little effect on concrete performances and micropores with more than 100 nm diameter are considered harmful to concrete performances. 63 The MIP test was used in order to explain the effect of the SF on the pore size of matrix in CPCGA. Approximately rough 3 g of specimens from the 20 g representative specimens were tested with the parameters set at 485 dyn/cm for Hg surface tension and 130 for contact Angle, 64 and the test results are shown in Table 4.…”

Section: Porosity Of the Itzmentioning

confidence: 99%

Properties and Microstructure of an Interfacial Transition Zone Enhanced by Silica Fume in Concrete Prepared with Coal Gangue as an Aggregate

Wang,

Li,

Zhong

et al. 2023

ACS Omega

View full text Add to dashboard Cite

The wide application of concrete prepared with coal gangue (CG) as an aggregate (CPCGA) is limited because of the low mechanical strength and strong water absorption capacity of CG. This paper used silica fume (SF) to improve the performance of the interfacial transition zone (ITZ) in CPCGA and revealed the enhancement mechanism. The results showed that the compressive strength of CPCGA prepared with cement replaced by a suitable amount of SF at the age of 28 days increased by more than 30%, and the flexural strength increased by over 20%. The SF could effectively reduce the porosity and micropore size in the ITZ of CPCGA, and the porosity of the ITZ in CPCGA added with 7.50% SF decreased by 44.22, 46.16, and 24.46% at distances from the aggregate surface of 10, 50, and 100 μm, respectively, compared with CPCGA without SF. Further research showed that Ca(OH)2 (CH) generated in the cement hydration reaction reacted with a large amount of active SiO2 in SF to restrain the formation of coarse CH in the ITZ of CPCGA, and the calcium silicate hydrate (C–S–H) gel generated filled the ITZ micropores to reduce the ITZ porosity further. Moreover, the reaction of SF and CH helped to promote the hydration reaction of cement to proceed thoroughly in CPCGA, thus improving CPCGA performance.

show abstract

“…In the study [25], presoaked CRCA underwent an accelerated carbonation process. They performed mechanical testing on the concrete, such as compressive, splitting tensile, and flexural strength tests, and micro-property tests, such as Vickers micro-hardness (VMH), X-ray diffraction, and scanning electron microscope-energy dispersive spectroscopy (SEM-EDS).…”

Section: The Effect Of Crca On Microstructural Properties Of Concretementioning

confidence: 99%

Review on the Importance of Coarse Recycled Concrete Aggregates as Alternative Construction Materials

Kareem,

Sahoo

2024

Advanced Materials in Civil Engineering

View full text Add to dashboard Cite

Recycled concrete aggregates are one of the most important supplementary building materials used in the production of "green concrete" or recycled aggregate concrete. They are collected from construction and demolition trash, which decreases construction industry waste (RAC). By size, aggregates are divided into coarse and fine aggregate. Focus of research is on the replacement of coarse aggregate in concrete using coarse recycled concrete aggregate (CRCA). It is vital to provide a major overview on the main developments and advancements in the characterization of CRCA and in the comprehension of the behaviour of concrete containing this, taking into account its varied attributes such as freshness, hardness, and durability. Because of the weak attached mortar present on its surface, CRCA's performance in all areas falls as the replacement percentage rises. Different treatments such as washing and drying of aggregate, changed mixing sequences, carbonation, slurry and microbiological treatments, CO2 mineralization and air jigging process can mitigate the negative effects of CRCA in the concrete. This study discusses the issues raised by the widespread use of CRCA on concrete and the effectiveness of the numerous treatment solutions that are now available in the industry.

show abstract

Effects of Carbonated Recycled Concrete Aggregate on Mechanical Properties of Concrete and Micro-Properties of Interfacial Transition Zone

Cited by 6 publications

References 35 publications

Experimental Studies to Investigate Efficacies of Granite Porphyry Powder as Homologous Manufactured Sand Substitute

Experimental Studies to Investigate Efficacies of Granite Porphyry Powder as Homologous Manufactured Sand Substitute

Properties and Microstructure of an Interfacial Transition Zone Enhanced by Silica Fume in Concrete Prepared with Coal Gangue as an Aggregate

Review on the Importance of Coarse Recycled Concrete Aggregates as Alternative Construction Materials

Contact Info

Product

Resources

About