scholarly journals Characteristics of Blended Cements Produced from Selected Hardwood Ashes

2018 ◽  
Vol 3 (1) ◽  
Author(s):  
Akeem A Raheem ◽  
Blessing O Orogbade
Keyword(s):  
Chemical Composition ◽  
Wood Ash ◽  
Heat Of Hydration ◽  
Cement Clinker ◽  
Potassium Oxide ◽  
Cassia Siamea ◽  
Suitable Material ◽  
Blended Cements ◽  
Setting Times ◽  
Portland Cement Clinker

In an attempt to find an alternative binding material for construction industry, this study considered the use of wood ash from three different hardwoods namely: Tectonagrandis, Cassia siamea and Vitellariaparadoxa as a pozzolan in cement production. The study investigates the chemical composition (silica (SiO2), aluminum oxide (Al2O3), ferric oxide (Fe2O3), calcium oxide (CaO), magnesium oxide (MgO), sulphur trioxide (SO3), sodium oxide (Na2O) and potassium Oxide (K2O)) of the ashes and the clinker. The production of blended cements were carried out in the factory by replacing 5- 50% by weight of Ordinary Portland Cement Clinker with the ashes during the manufacturing process. The cement without wood ash serves as the control. The physical characteristic (fineness, initial and final setting times, heat of hydration and residue on 45µm sieve), and the chemical composition of the blended cements were also investigated. The results showed that all the wood ashes (Tectonagrandis ash (TGA), Cassia siamea ash (CSA) and Vitellariaparadoxa ash (VPA)) were suitable material for use as pozzolan since they satisfied the requirement for such a material by having a combined SiO2, Fe2O3 and Al2O3 of more than 70%. The TGA, CSA and VPA blended cements satisfied standard requirements for up to 20% replacement level. It was concluded that all the wood ashes were suitable for use in the production of blended cements.

scholarly journals Chemical and Physical Characteristics of Blended Cements Produced from Softwood Ash

2018 ◽  
Vol 1 (March 2018) ◽  
pp. 1-7
Author(s):  
B.O Orogbade ◽  
A.A Raheem
Keyword(s):  
Chemical Composition ◽  
Wood Ash ◽  
Heat Of Hydration ◽  
Cement Clinker ◽  
Potassium Oxide ◽  
Agricultural Residue ◽  
Suitable Material ◽  
Blended Cements ◽  
Setting Times ◽  
Portland Cement Clinker

In an attempt to convert agricultural residue to alternative binding material for use in construction industry, this research considered the use of wood ash from Anacardium- occidentale (kaju) wood which is softwood as a pozzolan in cement production. In this study, the chemical composition (silica (SiO.), aluminum oxide (AI,O,), ferric oxide (Fe,O,), calcium oxide (CaQ), magnesium oxide (MgO), sulphur trioxide (SO,), sodium oxide (Na,O) and potassium Oxide (K,O)) of the ashes and the clinker was investigated. The production of blended cements were carried out in the factory by replacing 5- 50% by weight of Ordinary Portland Cement Clinker with the ashes during the manufacturing process. The cement without wood ash serves as the control. The physical characteristic (fineness, initial and final setting times, heat of hydration and residue on 45um sieve), and the chemical composition of the blended cements were also investigated. The results showed that Anacardiumoccidentale ash (AOA) was a suitable material for use as pozzolan since it satisfied the requirement for such a material by having a combined SiO, Fe,O,and Al,O,of more than 70% according to ASTM C 618. The AOA blended cements satisfied standard requirements for up to 20% replacement level. It was concluded that the wood ash was suitable for use in the production of blended cements.

scholarly journals Hydration behaviour of limestone-calcined clay and limestone-slag blends in ternary cement

2021 ◽  
Vol 6 ◽  
pp. 17-24
Author(s):  
Anuj Parashar ◽  
Shashank Bishnoi
Keyword(s):  
Bound Water ◽  
Heat Of Hydration ◽  
Cement Clinker ◽  
Strength Development ◽  
Gravimetric Analysis ◽  
Calcined Clay ◽  
X Ray ◽  
Blended Cements ◽  
Degree Of Hydration ◽  
Hydration Behaviour

The effect of kaolinitic calcined clay and slag on the hydration of limestone-containing ternary blended cements was investigated. The effect of alumina from different sources of SCMs was considered to activate the formation of carboaluminates. Ternary blends with 50% ordinary portland cement clinker, 45% blends of limestone calcined clay (LC2) in 1:2 blend and slag limestone blend (SLS) in 2:1 mix proportion with 5% of gypsum were studied. The hydration behaviour was analysed based on cement mortar compressive strength, heat of hydration using an isothermal calorimeter and bound water measured using thermal gravimetric analysis (TGA). In addition, the degree of hydration of clinker phases and the composition of calcium - alumino - silicate - hydrate (C-A-S-H) gels forming in two different systems were compared on 90 days hydrated samples analysed using X-Ray diffractometry (XRD) and scanning electron microscopy - energy dispersive X-ray spectroscopy (SEM-EDX) respectively. The results show a rapid early strength development in limestone calcined clay cement blend (LC3) but a lower clinker hydration in comparison with slag limestone cement blend (SLSC) at later ages. In both the cement blends the formation of hemicarboaluminate (Hc) and monocarboaluminate (Mc) was confirmed at 90 days, but the conversion of Hc to Mc was higher in SLSC. Results further confirmed a lower degree of hydration and higher alumina incorporation in the C-A-S-H gel in the LC3 comparison to SLSC. The presence of calcium hydroxide was also confirmed in the SLSC blend due to the hydraulic nature of slag that supported the later age conversion of Hc to Mc as not seen in LC3.

scholarly journals Application of the system-object approach to simulation of the conversion of raw materials into a portlandcement clinker

2021 ◽  
Vol 6 (3) ◽  
pp. 65-71
Author(s):  
Nikita G. Reznikov ◽  
◽  
Alexander G. Zhikharev ◽  
Keyword(s):  
Experimental Data ◽  
Chemical Composition ◽  
Portland Cement ◽  
Simulation Model ◽  
Raw Materials ◽  
Cement Clinker ◽  
Simulation Environment ◽  
Portland Cement Clinker ◽  
Two Component

The article discusses the construction of a simulation model of the abstract process of converting raw materials into Portland cement clinker in the UFOModeler simulation environment. An algorithm for generating a pseudo-random oxide (chemical) composition of components based on experimental data of real production and calculation for two-component and three-component raw mixtures has been developed. An algorithm for calculating the main indicators of the composition of clinker based on. The analysis of the obtained results is carried out.

scholarly journals The effects of seawater and nanosilica on the performance of blended cements and composites

2020 ◽  
Vol 10 (12) ◽  
pp. 5009-5026 ◽  
Author(s):  
Pawel Sikora ◽  
Didier Lootens ◽  
Maxime Liard ◽  
Dietmar Stephan
Keyword(s):  
Transport Properties ◽  
Reaction Rate ◽  
Mechanical Performance ◽  
Setting Time ◽  
Blended Cement ◽  
Heat Of Hydration ◽  
Strength Development ◽  
Cement Pastes ◽  
Blended Cements ◽  
Setting Times

AbstractThis study investigates the effects of seawater and nanosilica (3% by weight of cement), on the fresh and hardened properties of cement pastes and mortars produced with two types of low heat cements: Portland pozzolana cement (CEM II) and blast furnace cement (CEM III). The heat of hydration, initial and final setting times, rheological properties, strength development, sorptivity and water accessible porosity of the cement pastes and mortars were determined. The data reveal that cement type has a significant effect on the reaction rate of cement with seawater and nanosilica (NS). Specimens produced with slag-blended cement exhibited a higher cement reaction rate and the composite produced exhibited better mechanical performance, as a result of the additional reaction of alumina rich phases in slag, with seawater. Replacement of freshwater with seawater contributes mostly to a significant improvement of early strength. However, in the case of slag-blended cement, 28 day strength also improved. The incorporation of NS results in additional acceleration of hydration processes, as well as to a decrease in cement setting time. In contrast, the addition of NS results in a noticeable increment in the yield-stress of pastes, with this effect being pronounced when NS is mixed along with seawater. Moreover, the use of seawater and NS has a beneficial effect on microstructure refinement, thus improving the transport properties of cement mortars. Overall, the study has showed that both seawater and NS can be successfully used to accelerate the hydration process of low heat blended cements and to improve the mechanical and transport properties of cement-based composites.

Canadian use of ground granulated blast-furnace slag as a supplementary cementing material for enhanced performance of concrete

2000 ◽  
Vol 27 (4) ◽  
pp. 754-760 ◽  
Author(s):  
R Doug Hooton
Keyword(s):  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Large Scale ◽  
Heat Of Hydration ◽  
Chloride Ingress ◽  
Blended Cements ◽  
Setting Times ◽  
Granulated Blast Furnace Slag ◽  
Cementing Material ◽  
Furnace Slag

The performance of concrete, in terms of its placeability, physical properties, and its durability, can be enhanced by the use of slag-blended cements or separately added ground granulated blast-furnace slag. It also has advantages for architectural purposes due to the whiteness it imparts to concrete. Properly proportioned and cured slag concretes will control deleterious alkali-silica reactions, impart sulphate resistance, greatly reduce chloride ingress, and reduce heat of hydration. Setting times and early age strengths can be controlled through appropriate proportioning, while later age properties are typically enhanced. CSA and ASTM standards cover both slag-blended cements (CSA A362; ASTM C595; ASTM C1157) and slag as a supplementary cementing material (CSA A23.5; ASTM C989). Since Lafarge introduced the first large-scale slag grinding plant near Hamilton in 1976, slag has become the predominant supplementary cementing material in Ontario. Recently, its availability in the U.S. has expanded dramatically.Key words: blast-furnace slag, concrete performance, supplementary cementing material.

scholarly journals Determination of Selected Physical and Chemical Characteristics of Neem Seed Husk Ash Blended Cement

2019 ◽  
Vol 2 (Issue 1) ◽  
Author(s):  
A.A Raheem ◽  
E.O Ibiwoye
Keyword(s):  
Chemical Composition ◽  
Setting Time ◽  
Blended Cement ◽  
Heat Of Hydration ◽  
Neem Seed ◽  
Initial Setting Time ◽  
Blended Cements ◽  
Final Setting Time ◽  
Total Percentage ◽  
Seed Husk

Neem tree (Azadirachtaindica) is a tropical evergreen tree scattered all over the country, hence its availability can add to the list of materials used as pozzolan. This study investigated the characteristics of Neem Seed Husk Ash (NSHA) blended cement produced in the factory. Neem fruit was collected from Olooru town and Ilorin metropolis in Kwara State Nigeria, after collection, the seed was removed with the use of Decorticator huskers, sun dried for 3 days to reduce its moisture content and burnt in a furnace at a temperature of 650 ± 50 oC. The chemical composition (SiO2, Al2O3 and Fe2O3) and physical characteristics were determined. Blended cement was produced by intergrinding 5, 10, 15, 20, 25, 30, 35, 40, 45 and 50% by weight of NSHA with Ordinary Portland Cement (OPC) clinker and gypsum. OPC without NSHA served as the control. The blended cements produced were analyzed for chemical composition using X-Ray Flourescence Analyser (XRF). The physico-mechanical properties of blended cement (fineness, initial and final setting time, heat of hydration) produced was examined. The total percentage of SiO2, Al2O3 and Fe2O3 for NSHA is 75.35%. Factory produced NSHA – blended cement is suitable as it satisfied the maximum requirement of 375 minutes for final setting time and 45 minutes minimum initial setting time, hence it can be used for construction work where strength is not a priority

Production and Characterization of Wood Ash Pozzolan of Melina and Cashew Tropical Woods

2020 ◽  
Vol 11 (10) ◽  
pp. 735-742
Author(s):  
Annune J. Eric ◽  
Nwafor Christiana ◽  
Shawon M. Caesar ◽  
Ahmed Yakubu Ahmed
Keyword(s):  
Chemical Composition ◽  
Aluminum Oxide ◽  
Construction Industry ◽  
Wood Ash ◽  
Potassium Oxide ◽  
Cement Production ◽  
Binding Material ◽  
Sulphur Trioxide ◽  
Tropical Woods

In an attempt to find an alternative binding material for construction industry, this study considered the use of wood ash from two different hardwoods namely: Melina wood ash and Cashew wood ash as a pozzolan in cement production. The study investigates the chemical composition (silica (SiO2), aluminum oxide (Al2O3), ferric oxide (Fe2O3), calcium oxide (CaO), magnesium oxide (MgO), sulphur trioxide (SO3), sodium oxide (Na2O) and potassium Oxide (K2O)) of the ashes and the clinker.

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