Use of grinded hardened cement pastes as mineral addition for mortars

Bouarroudj, Mohamed Elkarim; Rémond, Sébastien; Bulteel, D.; Potier, Guillaume; Michel, Frédéric; Zhao, Zengfeng; Courard, Luc

doi:10.1016/j.jobe.2020.101863

Cited by 17 publications

(16 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Finally, the decarbonation is observed with a small peak for the different pastes above 900 • C. The cement paste (C) has a much weaker decarbonation peak compared to the other mixtures due to the lower content of calcite CaCO 3 . A significant quantity of calcite has been observed in the slag paste compared to the different pastes based on slag and calcined sediment at a rate of 10%, 15% and 20% [61] in which the sediment replaces roughly one-third of the slag.…”

Section: Thermogravimetry Analysis (Tg/dtg) Of Different Mixturesmentioning

confidence: 96%

Mechanical Properties and Microstructure of Low Carbon Binders Manufactured from Calcined Canal Sediments and Ground Granulated Blast Furnace Slag (GGBS)

et al. 2021

View full text Add to dashboard Cite

This research study evaluated the effects of adding Scottish canal sediment after calcination at 750 °C in combination with GGBS on hydration, strength and microstructural properties in ternary cement mixtures in order to reduce their carbon footprint (CO2) and cost. A series of physico-chemical, hydration heat, mechanic performance, mercury porosity and microstructure tests or observations was performed in order to evaluate the fresh and hardened properties. The physical and chemical characterisation of the calcined sediments revealed good pozzolanic properties that could be valorised as a potential co-product in the cement industry. The results obtained for mortars with various percentages of calcined sediment confirmed that this represents a previously unrecognised potential source of high reactivity pozzolanic materials. The evolution of the compressive strength for the different types of mortars based on the partial substitution of cement by slag and calcined sediments showed a linear increase in compressive strength for 90 days. The best compressive strengths and porosity were observed in mortars composed of 50% cement, 40% slag and 10% calcined sediment (CSS10%) after 90 days. In conclusion, the addition of calcined canal sediments as an artificial pozzolanic material could improve strength and save significant amounts of energy or greenhouse gas emissions, while potentially contributing to Scotland’s ambitious 2045 net zero target and reducing greenhouse gas emissions by 2050 in the UK and Europe.

show abstract

Section: Thermogravimetry Analysis (Tg/dtg) Of Different Mixturesmentioning

confidence: 96%

Mechanical Properties and Microstructure of Low Carbon Binders Manufactured from Calcined Canal Sediments and Ground Granulated Blast Furnace Slag (GGBS)

et al. 2021

View full text Add to dashboard Cite

show abstract

“…The second is a ground hardened cement paste (GHCP) and the third one is ground brick (GB). The GHCP and GB are mineral additions produced from HCP and brick, which can be considered as model materials for CDWs (as in [14][15][16][17][18][19][20][21]). The LP is used as a reference mineral addition and supposed non-porous.…”

Section: Materials Preparationmentioning

confidence: 99%

“…However, when a porous mineral addition is used, part of this water is absorbed which decreases the amount of water available for cement hydration and for the fluidification of the fresh mixture. In a similar research Bouarroudj et al [21] take into consideration the intra granular porosity present in the ground model RCA (composed from hardened cement paste) to correct the amount of water introduced into the mix. They show that substituting the cement by ground RCA with taking into account the water absorption of the powder allows controlling the effective water and maintain the fluidity of the mix.…”

mentioning

confidence: 99%

Intra granular porosity of mineral powders: modeling and experimentation

et al. 2021

Self Cite

View full text Add to dashboard Cite

Recycled concrete aggregate (RCA) possess high water absorption, due to the porosity of the attached hardened cement paste they contain. Fine particles of RCA are composed of larger amounts of hardened cement paste, which makes their valorization even more difficult in concrete or mortar. One way to valorize these fine particles could be to use them as mineral addition, however their water absorption coefficient has to be determined, which is tricky for powders. The objective of this work is to estimate the remaining intra granular porosity of a ground powder using two different original approaches. The first modelling approach considers that the porous monolith material is composed of series of pores with characteristic volumes. A pore is considered opened due to grinding if it is cut by the surface of the particle and if its size is larger than the smallest inter granular pore. The remaining porosity after grinding is computed from the pore size distribution of the monolith material and the particle size distribution of the powder. The second experimental approach is based on mercury intrusion porosimetry tests performed on the powder. The separation between inter and intra granular porosity allows the estimation of the powder's remaining porosity. The obtained results show a good agreement between the two approaches in the case of disconnected pores. However, in the case of connected porosity, the experimental approach over estimates the amount of inter-granular porosity.

show abstract

“…HCPC in fine RCA is closely related to other physical and mechanical properties (e.g., density and water absorption) of fine RCA, which play an important role in concrete formulation [23,36]. Indeed, the water absorption of fine RCA has to be accurately quantified to assess the effective water used in concrete [37][38][39][40][41][42]. However, the current methods (such as EN 1097-6 [43] or ASTM C 128 [44], IFSTTAR No.…”

Section: Introductionmentioning

confidence: 99%

Quantification of the Hardened Cement Paste Content in Fine Recycled Concrete Aggregates by Means of Salicylic Acid Dissolution

et al. 2022

Self Cite

View full text Add to dashboard Cite

Adherent hardened cement paste attached to recycled concrete aggregates (RCA) generally presents a higher porosity than natural aggregates, which induces a lower porosity in the properties of RCA. The characterization of the adherent hardened cement paste content (HCPC) in the fine RCA would promote better applications of RCA in concrete, but the determination of HCPC in fine RCA is not well established. A simple method based on salicylic acid dissolution was specifically developed to quantify the HCPC in RCA, especially for RCA containing limestone aggregates. The results demonstrated that the soluble fraction in salicylic acid (SFSA) was equal to the HCPC for white cement and slightly lower for grey Portland cement, which was also confirmed by a theoretical approach using modelling the hydration of cement paste with the chemical equations and the stoichiometric ratios. The physical and mechanical properties of RCA (e.g., water absorption) were strongly correlated to the SFSA. For industrial RCA, SFSA did not give the exact value of HCPC, but it was sufficient to correlate HCPC with the other properties of RCA. The water absorption could be estimated with good accuracy for very fine RCA (laboratory-manufactured RCA or industrial RCA) by extrapolating the relationship between water absorption and HCPC, which is very important for concrete formulation.

show abstract

Use of grinded hardened cement pastes as mineral addition for mortars

Cited by 17 publications

References 29 publications

Mechanical Properties and Microstructure of Low Carbon Binders Manufactured from Calcined Canal Sediments and Ground Granulated Blast Furnace Slag (GGBS)

Mechanical Properties and Microstructure of Low Carbon Binders Manufactured from Calcined Canal Sediments and Ground Granulated Blast Furnace Slag (GGBS)

Intra granular porosity of mineral powders: modeling and experimentation

Quantification of the Hardened Cement Paste Content in Fine Recycled Concrete Aggregates by Means of Salicylic Acid Dissolution

Contact Info

Product

Resources

About