Effect and mechanism of surface-coating pozzalanics materials around aggregate on properties and ITZ microstructure of recycled aggregate concrete

Kong, Deyu; Lei, Ting; Zheng, Jianjun; Ma, Chao; Jiang, Jun; Jiang, Jing

doi:10.1016/j.conbuildmat.2009.10.038

Cited by 412 publications

(153 citation statements)

References 21 publications

Supporting

Mentioning

113

Contrasting

Unclassified

Order By: Relevance

“…It might be due to treatment solution type G contained a certain amount of sodium hydroxide as the alkaline activator for pozzolanic and sodium silicate, the amount of sodium hydroxide incompletely reacted with sodium silicate and pozzolanic powder, which caused a negative effect on the mechanical properties of the new concrete [30]. The compressive strength of RAC treated with SSF, SMK, and SFA enhanced about 28-36%, 13-29%, and 23-28% compared to that of untreated RAC, respectively, which is significantly higher than other observations in [10], [31]. It can be seen that the concentration of treatment solution considerably affected the compressive strength of RAC.…”

Section: Compressive Strengthcontrasting

confidence: 38%

“…In order to enhance the properties of RAC, several techniques have been developed [9]. Recently, using pretreating method for RCA such as surface modification treatment of RCA with pozzolanic admixtures is one of the solutions for improving the quality of RAC, saving consumption of energy and being environmentally friendly [10]. Pozzolanic admixtures such as fly ash (FA), silica fume (SF), metakaolin (MK), and blast furnace slag (GGBS) can enhance microstructure of RAC for two reasons: pozzolanic admixtures operate as a micro filler, filling in pores and cracks of RCA; pozzolanic materials will consume CH crystals in RAC to form C-S-H gel (CaO.SiO2.H2O) to fill up voids of RCA [11].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Enhancement of Recycled Aggregate Concrete Properties by a New Treatment Method

Bui

Satomi

Takahashi

2018

GEOMATE

View full text Add to dashboard Cite

ABSTRACT:Recently, decreasing natural sources of aggregate accompanied by increasing large quantities of construction and demolition waste (CDW) cause challenges for environment and construction industry. A significant solution for this is to recycle CDW as a new aggregate source for concrete. However, using recycled concrete aggregate (RCA) in concrete involves various obstacles and controversial issues in controlling the quality of recycled aggregate concrete (RAC). This study is an effort to improve the quality of RAC containing 100% coarse RCA by using pozzolanic and sodium silicate solution as new treatment solutions. This study examined performance abilities of RAC after being treated with new treatment solutions and a new mixing procedure. The mechanical properties of RAC were evaluated based on testing of concrete under various conditions. The significant results indicated that sodium silicate combined with pozzolanic materials can improve mechanical properties of RAC containing 100% coarse RCA. At 20% concentration of sodium silicate and silica fume, the compressive strength of RAC could improve up to 36%. Achievements of this approach demonstrated its effectiveness in enhancing the strength of RAC, which is potentially applied to treating RCA for concrete in the future.

show abstract

Section: Compressive Strengthcontrasting

confidence: 38%

Section: Introductionmentioning

confidence: 99%

Enhancement of Recycled Aggregate Concrete Properties by a New Treatment Method

Bui

Satomi

Takahashi

2018

GEOMATE

View full text Add to dashboard Cite

show abstract

“…Therefore, in order to reduce the chloride diffusion coefficient of RAC, D om and R rm need to be decreased by reducing the water/binder ratio and using pre-soaking approaches , carbonizing recycled aggregate (Kou et al 2014), and triple mixing method (Kong et al 2010). …”

Section: Sensitivity Analysismentioning

confidence: 99%

On Probability Distribution of Chloride Diffusion Coefficient for Recycled Aggregate Concrete

Ying

Xiao

Meng

2016

Int J Concr Struct Mater

View full text Add to dashboard Cite

In predicating the probability distribution of chloride diffusion coefficient of recycled aggregate concrete (D RAC ), the morphological characteristics of three phases, i.e., the old attached mortar, the natural aggregate and the new mortar, should all be taken into account. The present paper attempts to develop a probability density evolution method (PDEM) to achieve this. After verifying the derived PDEM results with experimental results, the effects of old attached mortar to the D RAC are examined in a quantitative manner. It is found that (1) the variation of the attached mortar content is much sensitive to D RAC ; (2) given the probability distribution of the content and chloride diffusion coefficient of old mortar, the probability distribution of D RAC can be analysed based on the PDEM; and (3) the critical chloride diffusion coefficient at a certain assurance rate can be obtained by the PDEM. The analysis results of this investigation will be valuable to the durability design for RAC.

show abstract

“…7 and 8 that RAC made with RCA obtained approximately the same strength as the corresponding CT concrete. The slightly greater strength of the RA concrete relative to the CT concrete may be attributed to a stronger bond developed at the ITZ between the old mortar and the original aggregate of RAC (which was obtained from the concrete with the compressive strength of approximately 50 MPa) (38)(39)(40); therefore, the strengthcontrolling link of the RA concrete was the ITZ between the new mortar and the RCA, where the interfacial bond was the weakest phase in the concrete. These results are similar to those in previous studies (41,42).…”

Section: Compressive Strengthmentioning

confidence: 99%

Influence of bagasse ash and recycled concrete aggregate on hardened properties of high-strength concrete

et al. 2018

View full text Add to dashboard Cite

ABSTRACT:This research aimed to use of bagasse ash as a cement replacement in high-strength recycled aggregate concrete (HS-RAC). Crushed limestone was replaced with 100% recycled concrete aggregate (RCA) and the ground bagasse ash (GBA) was used to partially replace ordinary Portland cement (OPC) at 20, 35 and 50%wt of binder to cast HS-RAC. The results indicated that the replacing of crushed limestone with RCA had a negative impact on the properties of the concrete. Increasing the amount of GBA in HS-RAC resulted in a decrease in density and an increase in the volume of permeable pore space. The concrete mixtures prepared with 20%wt GBA replacement of OPC promoted greater the compressive strength than the conventional concrete (CT concrete) at 90 days or more. HS-RAC with GBA (up to 50%) was more durable in terms of chloride ion penetration resistance, although it had lower compressive strength than the CT concrete. RESUMEN: Influencia de la ceniza de bagazo y los áridos de hormigón reciclado en las propiedades de endurecimiento de hormigones de alta resistencia.En esta investigación se utilizó ceniza de bagazo como sustituto del cemento en hormigón de alta resistencia con áridos reciclados (HS-RAC). La piedra caliza fue sustituida por un árido 100% reciclado de hormigón y la ceniza de bagazo molida (GBA) en diferentes porcentajes (20, 35 y 50% en peso del material cementante) fue utilizada para reemplazar parcialmente al cemento Portland para producir hormigón de tipo HS-RAC. Los resultados indicaron que la sustitución de la piedra caliza molida por áridos de hormigón reciclado tiene un efecto negativo en las propiedades del hormigón. Aumentar la cantidad de GBA en el HS-RAC redujo la densidad e incrementó el volumen del espacio de los poros permeables. Las mezclas de hormigón preparadas reemplazando 20% en peso del cemento Portland por ceniza de bagazo molida presentaron mayor resistencia a la compresión que el hormigón convencional a los 90 días o más. El HS-RAC con GBA (hasta 50%) tuvo una durabilidad mayor que el hormigón convencional en términos de resistencia a la penetración de iones de cloruro, a pesar de tener una menor resistencia a la compresión.PALABRAS CLAVE: Hormigón; Árido; Resistencia a la compresión; Durabilidad; Cloruros ORCID ID: P. Rattanachu

show abstract

Effect and mechanism of surface-coating pozzalanics materials around aggregate on properties and ITZ microstructure of recycled aggregate concrete

Cited by 412 publications

References 21 publications

Enhancement of Recycled Aggregate Concrete Properties by a New Treatment Method

Enhancement of Recycled Aggregate Concrete Properties by a New Treatment Method

On Probability Distribution of Chloride Diffusion Coefficient for Recycled Aggregate Concrete

Influence of bagasse ash and recycled concrete aggregate on hardened properties of high-strength concrete

Contact Info

Product

Resources

About