scholarly journals Effect of Limestone Addition on Physicochemical Properties of Cement: A Case Study of Laboratory Prepared Portland Cement, Sokoto Portland Cement and Dangote Portland Cement

2020 ◽  
pp. 1-10
Author(s):  
Saidu Rabiu Saidu ◽  
Danhalilu Rabiu Lawal
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Physicochemical Properties ◽  
Ordinary Portland Cement ◽  
X Ray ◽  
Setting Times

Sokoto Ordinary Portland Cement, Dangote Ordinary Portland Cement and synthesized Portland Cement were blended with various proportions of limestone. X-Ray fluorescence (XRF) studies revealed increase in CaO concentration with addition limestone in all samples studied, while the concentration of other oxide decreases. Compressive strength decreases as limestone content increases but at lower concentration (5-15%), the cured cement had appreciable strength, which also decreases with addition of limestone for all the samples. Soundness test revealed that addition of limestone within 5-15% did not cause any expansion and weakening of the cement structure. The setting times for all cement types decreases with increasing limestone addition.

Experimental Study on Compatibility between Alkali-Free Liquid Concrete Accelerators and Cement

2013 ◽  
Vol 438-439 ◽  
pp. 102-107 ◽  
Author(s):  
Wen Kang Guo ◽  
Li Wang ◽  
Shu Yin Wang ◽  
Dao Yin Lan ◽  
Sheng Ping Li
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Compressive Strength ◽  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Strength Ratio ◽  
Setting Times ◽  
Gypsum Content ◽  
Durability Of Concrete

This paper selected two kinds of alkali-free liquid concrete accelerators and tested their compatibility with ordinary Portland cement, Portland cement and moderate heat Portland cement by measuring the setting times, compressive strength and compressive strength ratio of samples. The results showed that the compatibility is good between alkali-free accelerators and two types of cement: ordinary Portland cement and moderate heat Portland cement. However, the compatibility of two accelerators and Portland cement are quite different, the compatibility of AFA-2 accelerator is excellent, but AFA-1 accelerator is very poor. The setting times of alkali-free accelerators is mainly influenced by the mixing materials content, gypsum content, C3A and C3S content. In order to ensure the mechanical properties and durability of concrete, the setting times of new concrete accelerator is not the shorter the better, the appropriate initial and final setting times are 1min30s~5min and 4min~ 12min respectively.

Utilization of ashes from oil-palm wastes as a cement replacement material

1996 ◽  
Vol 34 (11) ◽  
pp. 185-192
Author(s):  
Joo-Hwa Tay ◽  
Kuan-Yeow Show
Keyword(s):  
Adverse Effect ◽  
Compressive Strength ◽  
Portland Cement ◽  
Oil Palm ◽  
Ordinary Portland Cement ◽  
Blended Cement ◽  
Ash Content ◽  
Palm Fruit ◽  
Cement Replacement ◽  
Setting Times

This study examines the engineering feasibility of utilizing the ashes derived from oil-palm fruit bunches, shell and fiber wastes as a cement replacement material. The experimental results indicate that blended cement containing ash derived from oil-palm wastes shows satisfactory setting times and soundness. Workability of concrete incorporating the ash is categorized as good, and no segregation was observed. The effects of ash addition on concrete density and water absorption are insignificant. Compressive strength of the concrete decreases with the ash content in the cement. At up to 10% by weight of shell-fiber ash addition, no adverse effect on strength was observed for the concrete cubes. The results suggest that the ash could possibly be blended in small amounts with ordinary Portland cement for concrete making.

The Effect of Nanoparticles of Ordinary Portland Cement (OPC) on Compressive Strength of Concrete

2014 ◽  
Vol 894 ◽  
pp. 342-348
Author(s):  
Abdoullah Namdar ◽  
Fadzil Mat Yahaya
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Construction Material ◽  
Simple Method ◽  
X Ray ◽  
Compressive Strength Of Concrete ◽  
Stability Of Structure ◽  
Scanning Electron

The quality of a construction material satisfies stability of structure. Several additives have been innovated for improve quality of compressive strength of concrete. In this paper for enhancement of compressive strength of concrete, a simple method has been proposed. The kaolin and bentonite have been treated by heat for duration of 1 hour, with constant temperature. For kaolin 200 oC, 400 oC, 600 oC, 800 oC, 1000 oC and 1200 oC of heat, and for bentonite 200 oC, 400 oC, 600 oC, 800 oC of heat has been subjected. The kaolin and bentonite treated by heat have been proposed as additive for concrete. The objective is to introduce an additive to improve compressive strength of concrete. The microstructure of modified Ordinary Portland Cement (OPC) paste has been investigated by using Field Emission Scanning Electron Microscopy (FESEM) and X-ray diffractometry (XRD). The results indicate that the best level of heat for produce additives from kaolin and bentonite, and illustrate quantity of additives for replace a portion of cement in concrete application. Modification of nanoparticles of cement paste during hydration has been discussed.

Study on Waterproof and Water-Resistant Properties of Gypsum

2012 ◽  
Vol 476-478 ◽  
pp. 1585-1588
Author(s):  
Hong Pan ◽  
Guo Zhong Li
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Portland Cement ◽  
Water Absorption ◽  
Ordinary Portland Cement ◽  
Experimental Results ◽  
Softening Coefficient

The comprehensively modified effect of cement, VAE emulsion and self-made acrylic varnish on mechanical and water-resistant properties of gypsum sample was investigated and microstructure of gypsum sample was analyzed. Experimental results exhibit that absolutely dry flexural strength, absolutely dry compressive strength, water absorption and softening coefficient of gypsum specimen with admixture of 10% ordinary Portland cement and 6% VAE emulsion and acrylic varnish coated on its surface can respectively reach to 5.11MPa , 10.49 MPa, 8.32% and 0.63, respectively.

scholarly journals The Effect of Nano Metakaolin Material on Some Properties of Concrete

2013 ◽  
Vol 6 (1) ◽  
pp. 50-61
Author(s):  
Amer M. Ibrahem ◽  
Shakir A. Al-Mishhadani ◽  
Zeinab H.Naji
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Portland Cement ◽  
Water Absorption ◽  
Thermal Activation ◽  
Ordinary Portland Cement ◽  
Splitting Tensile Strength ◽  
Kaolin Clay ◽  
Cement Ratio ◽  
Water Cement Ratio

This investigation aimed to study the effect of nano metakaolin ( NMK ) on some properties (compressive strength ,splitting tensile strength & water absorption ) of concrete. The nano metakaolin (NMK) was prepared by thermal activation of kaolin clay for 2 hours at 750 Ċ. The cement used in this investigation consists of ordinary Portland cement (OPC). The OPC was partially substituted by NMK of ( 3, 5 & 10%) by weight of cement. The C45 concrete was prepared , using water/cement ratio ( W/c) of (0.53) .The Water absorption was tested at 28 days while the tests (compressive strength ,splitting tensile strength) were tested at ages of (7, 28, 60,& 90) days . The compressive strength and splitting tensile strength of concrete with NMK were higher than that of reference concrete with the same W/c ratio.The improvement in the compressive strength when using NMK was (42.2, 55.8 , 63.1% ) at age 28 days for ( 3%, 5%, &10% ) replacement of NMK respectively whereas the improvement in the splitting tensile strength was (0% , 36% & 46.8 %) at age of 28 days when using (3%, 5%, &10% ) NMK respectively. The improvement in the water absorption was (16.6%, 21.79%, &25.6 ) when using (3, 5, &10% )NMK.

scholarly journals Utilization of Sugarcane Bagasse Ash from Power Co-generation Boilers as a Supplementary Cementitious Material

2021 ◽  
Vol 2 (2) ◽  
Author(s):  
Safiki Ainomugisha ◽  
Bisaso Edwin ◽  
Bazairwe Annet
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Sugarcane Bagasse ◽  
Low Income ◽  
Ordinary Portland Cement ◽  
Construction Material ◽  
Sustainable Construction ◽  
Partial Replacement ◽  
Hardened Concrete ◽  
Sugarcane Bagasse Ash

Concrete has been the world’s most consumed construction material, with over 10 billion tons of concrete annually. This is mainly due to its excellent mechanical and durability properties plus high mouldability. However, one of its major constituents; Ordinary Portland Cement is reported to be expensive and unaffordable by most low-income earners. Its production contributes about 5%–8% of global CO2 greenhouse emissions. This is most likely to increase exponentially with the demand of Ordinary Portland Cement estimated to rise by 200%, reaching 6000 million tons/year by 2050.  Therefore, different countries are aiming at finding alternative sustainable construction materials that are more affordable and offer greener options reducing reliance on non-renewable sources. Therefore, this study aimed at assessing the possibility of utilizing sugarcane bagasse ash from co-generation in sugar factories as supplementary material in concrete. Physical and chemical properties of this sugarcane bagasse ash were obtained plus physical and mechanical properties of fresh and hardened concrete made with partial replacement of Ordinary Portland Cement. Cost-benefit analysis of concrete was also assessed. The study was carried using 63 concrete cubes of size 150cm3 with water absorption studied as per BS 1881-122; slump test to BS 1881-102; and compressive strength and density of concrete according to BS 1881-116. The cement binder was replaced with sugarcane bagasse ash 0%, 5%, 10%, 15%, 20%, 25% and 30% by proportion of weight. Results showed the bulk density of sugarcane bagasse ash at 474.33kg/m3, the specific gravity of 1.81, and 65% of bagasse ash has a particle size of less than 0.28mm. Chemically, sugarcane bagasse ash contained SiO2, Fe2O3, and Al2O3 at 63.59%, 3.39%, and 5.66% respectively. A 10% replacement of cement gave optimum compressive strength of 26.17MPa. This 10% replacement demonstrated a cost saving of 5.65% compared with conventional concrete. 

scholarly journals Chloride Ingress in Chemically Activated Calcined Clay-Based Cement

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Joseph Mwiti Marangu ◽  
Joseph Karanja Thiong’o ◽  
Jackson Muthengia Wachira
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Strength Development ◽  
Chloride Ingress ◽  
Calcined Clay ◽  
Apparent Diffusion Coefficients ◽  
Apparent Diffusion ◽  
Lower Porosity ◽  
Lower Chloride

Chloride-laden environments pose serious durability concerns in cement based materials. This paper presents the findings of chloride ingress in chemically activated calcined Clay-Ordinary Portland Cement blended mortars. Results are also presented for compressive strength development and porosity tests. Sampled clays were incinerated at a temperature of 800°C for 4 hours. The resultant calcined clay was blended with Ordinary Portland Cement (OPC) at replacement level of 35% by mass of OPC to make test cement labeled PCC35. Mortar prisms measuring 40 mm × 40 mm × 160 mm were cast using PCC35 with 0.5 M Na2SO4 solution as a chemical activator instead of water. Compressive strength was determined at 28th day of curing. As a control, OPC, Portland Pozzolana Cement (PPC), and PCC35 were similarly investigated without use of activator. After the 28th day of curing, mortar specimens were subjected to accelerated chloride ingress, porosity, compressive strength tests, and chloride profiling. Subsequently, apparent diffusion coefficients (Dapp) were estimated from solutions to Fick’s second law of diffusion. Compressive strength increased after exposure to the chloride rich media in all cement categories. Chemically activated PCC35 exhibited higher compressive strength compared to nonactivated PCC35. However, chemically activated PCC35 had the least gain in compressive strength, lower porosity, and lower chloride ingress in terms of Dapp, compared to OPC, PPC, and nonactivated PCC35.

Quaternary blended cement mortars containing wood ash, glass and slag powders

2021 ◽  
Author(s):  
Eethar Thanon Dawood ◽  
Marwa Saadi Mhmood
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Glass Powder ◽  
Steel Slag ◽  
Wood Ash ◽  
Supplementary Cementitious Materials ◽  
Partial Replacement ◽  
Slag Powder ◽  
Steel Slag Powder

AbstractA quaternary supplementary cementitious materials as partial replacement of ordinary Portland cement decreases CO2 emission. This paper has investigated the properties of mortars made from different quaternary blends of wood ash, steel slag powder and glass powder with ordinary Portland cement at different replacement levels of 0, 24, 25, and 30% by weight of the binder. The blended mortar mixtures tested for flow, compressive strength and density. The results showed that the flow of mortars is decreased with the combined use of steel slag powder, glass powder, and wood ash compared with control mix. Compressive strength reduced with the combination of steel slag powder, glass powder and wood ash but this reduction effects is acceptable especially at 24% replacement contain super-plasticizer compared with the ecological benefit.

scholarly journals Physical Properties of Concrete Containing Graphene Oxide Nanosheets

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1707 ◽  
Author(s):  
Yu-You Wu ◽  
Longxin Que ◽  
Zhaoyang Cui ◽  
Paul Lambert
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Graphene Oxide ◽  
Flexural Strength ◽  
Portland Cement ◽  
Physical Properties ◽  
Ordinary Portland Cement ◽  
Construction Materials ◽  
Split Tensile Strength ◽  
Cement Pastes

Concrete made from ordinary Portland cement is one of the most widely used construction materials due to its excellent compressive strength. However, concrete lacks ductility resulting in low tensile strength and flexural strength, and poor resistance to crack formation. Studies have demonstrated that the addition of graphene oxide (GO) nanosheet can effectively enhance the compressive and flexural properties of ordinary Portland cement paste, confirming GO nanosheet as an excellent candidate for using as nano-reinforcement in cement-based composites. To date, the majority of studies have focused on cement pastes and mortars. Only limited investigations into concretes incorporating GO nanosheets have been reported. This paper presents an experimental investigation on the slump and physical properties of concrete reinforced with GO nanosheets at additions from 0.00% to 0.08% by weight of cement and a water–cement ratio of 0.5. The study demonstrates that the addition of GO nanosheets improves the compressive strength, flexural strength, and split tensile strength of concrete, whereas the slump of concrete decreases with increasing GO nanosheet content. The results also demonstrate that 0.03% by weight of cement is the optimum value of GO nanosheet dosage for improving the split tensile strength of concrete.

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