Physical and Chemo/Mechanical behaviors of fly ash and silica fume belite cement pastes- Part I

H.H.M, Darweesh

doi:10.34256/nnxt2121

Cited by 3 publications

(1 citation statement)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Ternary cement provides the opportunity to utilize the individual benefits of the binders simultaneously [24,25], where the replacement of cement with CSA in the ternary system ensures the reduction of CO2 emission as CSA production requires a lower lime content [26][27][28]. Improving the mechanical and durability properties of the cement mixes is another benefit that can be obtained while using CSA [4,[29][30][31][32][33].…”

Section: Introductionmentioning

confidence: 99%

Utilization of Oyster Shell Powder for Hydration and Mechanical Properties Improvement of Portland Cement Pastes

Darweesh¹

2023

JSMPM

View full text Add to dashboard Cite

Supplementary cementitious materials (SCMs) are usually partially substituted at the expense of Portland cement (OPC) to reduce, as possible, the CO2emission. There has been limited studies involved the use of Oyster shell (OS) to replace OPC. The current study investigated the properties of a ternary base batch containing Oyster shell powder (OSP).The ternary cement batch was consisting of OPC, granulated blast furnace slag (GbfS) and metakaolin (MK). The results indicated that the water consistency and setting times (initial and final) are gradually increased. The water absorption and total porosity are decreased, while the bulk density and combined water content increased. This behaviour continued up till 16 % OSP content, but then reverse was obtained with any further increase of OSP content. The same trend was achieved with the compressive strength. The addition of OSP often formed mono-and/or hemicarbonate instead of monosulfate because it is mainly composed of carbonates, and moreover it is stabilizing the formation of trisulphate or ettringite in the hydrated samples. The decrease is not the decrease of free lime contents proved that the OSP is a pozzolanic material. This was confirmed by FT-IR spectra. From the results it could be concluded that the optimum content of OSP was at most 16 %.

show abstract

Section: Introductionmentioning

confidence: 99%

Utilization of Oyster Shell Powder for Hydration and Mechanical Properties Improvement of Portland Cement Pastes

Darweesh¹

2023

JSMPM

View full text Add to dashboard Cite

show abstract

Durability and chemical resistance of nanoparticles fly ash and silica fume belite cement pastes against sulfate and chloride aggressive media- Part II

H.H.M

2021

NanoNEXT

View full text Add to dashboard Cite

The durability (chemical resistence) of the Portland cement (OPC), belite cement (BC) and the optimum belite cement (B4), which their physical and chemo/mechanical properties were perviously investigated in Part I, against 4 % MgSO4 and 4% MgCl2 solutions up to 12 months in terms of compressive strength, total sulfate and total chloride was evaluated and studied. Results showed that the optimum belite cement (B4) containing 15 % High pulverized fly ash (HPFA) and 5 % Silica fume (SF) could be resisted up to 6 months, while that of BC could be withstood only up to 5 months, and the OPC could not resist more than three months of immersion in 4% MgSO4 solution. The compressive strength values exhibited by the samples immesed in sulfate solution at 3, 5 and 6 months of immersion were 83.81, 76.38 and 91.13 MPa, respectively. The same trend was displayed when the same samples were exposed to 4% MgCl2 solution. The compressive strength values exhibited by the same samples exposed to chloride solution at 3, 5 and 6 months of immersion were 84.49, 82.23 and 93.32 MPa, respectively. The total sulfate and chloride contents were enhanced with immesion time up to 12 months, but their values were the minimum with B4 and the maximum with OPC, while with BC were the medium. The optimum cement batch (B4) achieved the highest resistance where it recorded the lowest values for sulfate and chloride ions, but the OPC exhibited the lowest resistance where it recorded the highest values of sulfate and chloride contents at all immersion ages till 12 months.

show abstract

Water Permeability, Strength Development And Microstructure of Activated Pulverized Rice Husk Ash Geopolymer Cement

H.H.M

2022

NanoNEXT

View full text Add to dashboard Cite

The activated pulverized rice husk ash (PRHA) as a pozzolanic material mixed with Portland cement (OPC) in various ratios was synthesized as geopolymer cement. The alkaline activator was prepared from a mixture of sodium hydroxide (NaOH) and sodium silicate (Na2SiO3). Effect of OPC replacement on the various properties of the synthesized geopolymers was evaluated. The results showed that the water of consistency sharply decreased with the increase of the OPC addition, while the setting times (initial and final) slightly decreased. The water absorption and apparent porosity reduced with OPC replacement at the expense of PRHA merely up to 18 wt. % content, and then increased. The bulk density as well as flexural and compressive strengths improved and enhanced also up to 18 wt. % OPC content, but then declined with any further increase. The free lime content increased up to 3 days of curing and then decreased onward due to its consumption during the pozzolanic reactions. The 18 wt. % OPC geopolymer mix is the optimum mix, where it achieved the better water absorption (6.89 %), bulk density (1.9099 g/cm3), apparent porosity (15.62 %), flexural strength (5.54 MPa) and compressive strength (58.25 MPa) at 90 days curing times. The ultrasonic pulse velocity test largely confirmed the obtained physical and mechanical characteristics. The FTIR spectra showed that the spectra of G18 geopolymer was more pronounced due to the formation of NASH geopolymer-gel needed to ensure better conformity between different constituents in the whole system that responsible for the improvements in the mechanical properties. The microstructure of the optimum G18 geopolymer mix is well-defined with no or little pores that responsible for the improving of physical properties and the enhancement of mechanical strengths, whereas the microstructure of G24 is more porous and heterogeneous matrix which was contributed to the reduction of mechanical strengths.

show abstract

Physical and Chemo/Mechanical behaviors of fly ash and silica fume belite cement pastes- Part I

Cited by 3 publications

References 36 publications

Utilization of Oyster Shell Powder for Hydration and Mechanical Properties Improvement of Portland Cement Pastes

Utilization of Oyster Shell Powder for Hydration and Mechanical Properties Improvement of Portland Cement Pastes

Durability and chemical resistance of nanoparticles fly ash and silica fume belite cement pastes against sulfate and chloride aggressive media- Part II

Water Permeability, Strength Development And Microstructure of Activated Pulverized Rice Husk Ash Geopolymer Cement

Contact Info

Product

Resources

About