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.

Experimental study on concrete with rice husk ash under sulphuric ACID solutions

2018 ◽  
Vol 7 (4.5) ◽  
pp. 522
Author(s):  
R. Ramya Swetha ◽  
Dr. G.Venkata Ramana ◽  
K. Anusha Hadassa
Keyword(s):  
Experimental Study ◽  
Compressive Strength ◽  
Portland Cement ◽  
Sulphuric Acid ◽  
Rice Husk ◽  
Industrial Waste ◽  
Ordinary Portland Cement ◽  
Rice Husk Ash ◽  
Acid Solutions ◽  
Iron And Calcium

This investigation shows the results on aggressive sulphuric acid on the concrete combined with rice husk ash (RH) when partially replaced for ordinary Portland cement. The husk ash, which mainly contains aluminum ion, silica, iron and calcium oxides, is an industrial waste and poses disposal problems. In this study, the effect of various concentrations (1%, 3%, 5%) of sulphuric acid (H2SO4) on Concrete replaced with various percentages (0%,5%,10%,15% and 20% by weight of cement) of RH is evaluated in-terms of residual compressive strength. The loss of compressive strengths of concrete immersed in various H2SO4 solutions for 7 days 28 days and 60 days indicates that at upto 10% replacement increase in strength was observed after which strengths were decreasing. This increase in strength is attributed to pozzolanic activity of RH.  

scholarly journals Mechanical Properties of OPC - Geocement Concrete

2019 ◽  
Vol 8 (4) ◽  
pp. 3733-3736
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Portland Cement ◽  
Ordinary Portland Cement ◽  
External Heat ◽  
Partial Replacement ◽  
Strength Development ◽  
Strength Increase ◽  
Heat Curing ◽  
Compressive Strength Development

Nowadays geopolymer concretes are subjected to heat curing. A large amount of highly corrosive and the hygroscopic alkaline activators are nowadays generally utilized in producing geopolymer concretes. In this paper, hybrid Ordinary Portland Cement (OPC) and geopolymer mixes are developed. The mainly used activator id the Solid potassium carbonate at different percentage is used as 5% & 10% of the weight of geopolymeric materials and OPC was blended with geopolymeric materials in different proportions. By adding cement, improves all the geopolymer properties except workability. By Applying external heat, it plays an important role in gaining strength. Strength gained by the absence of external heat is achieved by using Portland cement as a partial replacement of geocement. The influence of OPC content on the compressive strength development is investigated, and the optimized amount of solid activator to be used in the mix is also investigated. It is observed that percentage of strength increase decreases from52.24% to 14.77% as the OPC content increased from 20% to 60%.

Influence of Curing on Calcined Kaolin-Based Geopolymer

2016 ◽  
Vol 690 ◽  
pp. 200-205
Author(s):  
Narumon Lertcumfu ◽  
Sukum Eitssayeam ◽  
Kamonpan Pengpat ◽  
Tawee Tunkasiri ◽  
Denis Russell Sweatman ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Portland Cement ◽  
Microwave Heating ◽  
Production Line ◽  
Room Temperature ◽  
Ordinary Portland Cement ◽  
Microwave Curing ◽  
Alternative Material ◽  
Calcined Kaolin

The object of this work was to use calcined kaolin-based geopolymer as an alternative material to replace ordinary Portland cement (OPCs) by applying geopolymerization processes. Geopolymer slurry was prepared from calcined kaolin and alkali activators, which consisted of 10 M NaOH and Na2SiO3 solution. The fresh slurry was cast into plastic molds and then cured at room temperature for 24 h. Reaction temperatures were measured (for 24 hours after casting). Compressive strength of the geopolymer was tested after curing at room temperature and after microwave heating. The mechanical properties increased with added plaster for microwave curing of 5 min. It is believed that this process can increase the efficiency of the production line for geopolymer.

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.

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.

An Experimental Study on Reasonable Content of Slag in Concrete C30

2013 ◽  
Vol 312 ◽  
pp. 377-381
Author(s):  
Qing Fang Zhang
Keyword(s):  
Experimental Study ◽  
Compressive Strength ◽  
Portland Cement ◽  
Large Volume ◽  
Ordinary Portland Cement ◽  
Civil Engineering ◽  
Double Doping ◽  
Mix Proportion ◽  
Different Ages ◽  
Compressive Strength Of Concrete

This study used ordinary portland cement of 42.5 strength grade, mixed with various minerals and water reducer for the preparation of concrete C30 by means of four schemes, for each of which a specific mix proportion was employed. Accordingly the compressive strength of concrete with different preparations at different ages were compared. No matter which scheme was employed, single or double doping, with or without superplasticizer, the compressive strength of concrete at different ages was maximized when slag amount was 30% or maximum. Hence it can be concluded that the reasonable content of slag should be 30% for the preparation of concrete C30. It is suggested that the above results can be better applied to large-volume concrete, underground, harbor, road and bridge and civil engineering as well.

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.

Preparation and Mechanical Properties of Polyethylene-Portland Cement Composites

2009 ◽  
Vol 1242 ◽  
Author(s):  
Rivas-Vázquez L.P. ◽  
Suárez-Orduña R. ◽  
Valera-Zaragoza M. ◽  
Máas-Díaz A. De la L. ◽  
Ramírez-Vargas E.
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Portland Cement ◽  
Plastic Waste ◽  
Cement Composites ◽  
Compression Tests ◽  
Standard Samples ◽  
Cement Ratio ◽  
Reinforcing Fibers ◽  
Waste Polyethylene

ABSTRACTThe effects of waste polyethylene aggregate as admixture agent in Portland cement at different addition polyethylene/cement ratios from 0.0156 to 0.3903 were investigated. The reinforced samples were prepared according the ASTM C 150 Standard (samples of 5 × 5 × 5 cm). The reinforcing fibers were milling at a size of 1/25 in diameter, form waste and used them to evaluate the effects in mechanical properties in cement-based composites. The evaluation of polyethylene as additive was based on results of density and compression tests. The 28-day compressive strength of cement reforced with plastic waste at a replacement polyethylene/cement ratio of 0.0468 was 23.5 MPa compared to the control concrete (7.5 MPa). The density of cement replaced with polyethylene varies from 2.114 (0% polyethylene) to 1.83 g/cm3 by the influence of polyethylene.

Microstructure and Mechanical Properties of Ambiently-Cured Blended Coal Ash-Based Geopolymer Concrete

2016 ◽  
Vol 857 ◽  
pp. 400-404
Author(s):  
Tian Yu Xie ◽  
Togay Ozbakkaloglu
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Compressive Strength ◽  
Fly Ash ◽  
Bottom Ash ◽  
Coal Ash ◽  
Geopolymer Concrete ◽  
Mass Ratio ◽  
Blended Coal ◽  
Microstructure And Mechanical Properties

This paper presents the results of an experimental study on the behavior of fly ash-, bottom ash-, and blended fly and bottom ash-based geopolymer concrete (GPC) cured at ambient temperature. Four bathes of GPC were manufactured to investigate the influence of the fly ash-to-bottom ash mass ratio on the microstructure, compressive strength and elastic modulus of GPC. All the results indicate that the mass ratio of fly ash-to-bottom ash significantly affects the microstructure and mechanical properties of GPCs

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