INTRODUCTION
Strength and workability are both dominating factors in the making of concrete. Strength can be increased by increasing cement content but this in fact reduces the workability. Moreover,the water content can be increased for better workability, but this affects the strength. Hence,a perfect balance is to be maintained for both strength and workability. Furthermore, besides cement and water content, some other factors contribute greatly, which will be discussed as follows.
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Factors Affecting Strength And Workability Of Concrete
Methods of Concrete Mix Design For Medium Strength Concretes
INTRODUCTION
The available mix design methods are mostly dependent on charts, graphs and empirical relations from repetitive experiments following the same principle with a little bit of variations in different mix methods. Some of the commonly known design methods are-
1. Trial and Adjustment method of mix design
2. British DoE mix design method
3. ACI mix design method
4. Concrete mix proportioning-IS Guidelines
5. Rapid method for mix design
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Translucent Concrete
INTRODUCTION
Translucent concrete is a light transmitting concrete based building material. It works on the property of Nano-Optics. Its light transmitting is mainly due to uniform distribution of high numerical aperture Plastic Optic Fibres (POF) and hence it is also known as LiTraCon.It is produced by adding about 4% to 5% of optical fibres by volume in concrete mix. It was first mentioned in a Canadian Patent in the year 1935. As polymer based optical fibres and optical glass fibres were developed, it led to the increased rate of invention in this field.
Fig 1: Translucent Concrete building known as Lucem GmbH
COURTESY: BFT INTERNATIONAL
An Experimental Study of Human Hair in Concrete as Fibre Reinforcement
By
G. Ajaya Kumar O. Ganesh Kumar K. Damodar C. Jayasree Simpa Karmakar
Sai Ganapathi Engineering College, Visakhapatnam, Andhra Pradesh, India
Abstract— Since the ancient times, many researches and advancements were carried to enhance the physical and mechanical properties of concrete. Fiber reinforced concrete is one among those advancements which offers a convenient, practical and economical method for overcoming micro cracks and similar type of deficiencies. Since concrete is weak in tension hence some measures must be adopted to overcome this deficiency. Human hair is generally strong in tension; hence it can be used as a fiber reinforcement material. Human hair Fiber is an alternative non-degradable matter available in abundance and at cheap cost. It also reduces environmental problems. Also addition of human hair fibers enhances the binding properties, micro cracking control, Imparts ductility and also increases swelling resistance. The experimental findings in our studies would encourage future research in the direction for long term performance to extending this cost of effective type of fibers for use in structural applications. Experiments were conducted on concrete cubes, cylinders and beams of standard sizes with addition of various percentages of human hair fiber i.e., 0%, 0.5%, 1% and 1.5% by weight of cement, fine & coarse aggregate and results were compared with those of plain cement concrete of M-20 grade. For each percentage of human hair added in concrete, four cubes, three cylinders and three beams were tested for their respective mechanical properties at curing periods of 3 , 7 and 28 days. Optimum hair fiber content was obtained as 1.5% by weight of cement.
Keywords: Human Hair, Concrete, Fibre Reinforcement
Effect on Compressive Strength of Concrete by Addition of Polypropylene Fiber in M20 Grade of Concrete
By
1. Gursharan Singh
2. Er Harish Kumar
3. Professor Geetinder Kaur
4. Professor jaspreet Singh
Department of Civil Engineering and Technology.
Guru Kashi University. Talwandi Sabo, Punjab, India
Abstract- The paper deals with the effects of addition of various proportions of polypropylene fiber on the properties of high strength concrete m20 mixes.An experimental program was carried out to explore its effects on compressive strength under different curing condition. the main aim of the investigation program is to study the effect of polypropylene fiber mix by varying content such as 0%,0.5%,1%,1.5%,2% and find the optimum polypropylene fiber content.the concrete specimen were tested at different age level for mechanical properties of concrete name compressive strength of the concrete .a detailed study was carried out of curing conditions.the increase were compressive strength
KEYWORDS-Ordinary portland cement,polypropylene fiber, different curing condition.
Effect of Locust Bean Pod Extract As Water Reducing Admixture On The Compressive Strength Of Concrete.
By
ALFA UMAR
BSc. Civil engineering
Kaaf University College
ABSTRACT
This project present the investigatory result on the use of locust bean pod extract (LBPE) as a replacement for water on the Compressive strength of concrete. The locust bean pod is a waste material that is normally discarded after the seed have been harvested. 60 cubes of blocks of size 150 x 150 x 150mm were produced using locust bean pod extract as a blinder in concentration of 0, 0.15, 1.0, 1.5, 2.0 and 2.5kg/l respectively. The cubes without locust bean pod extract were used as control. The whole cube were cured under atmospheric condition in the laboratory and their compressive were determined. It was found that locust bean pod extract can significantly increase the compressive strength of the concrete block by 78.57% and that the concentration of the locust bean pod extract, the greater the compressive strength of the concrete cubes.
Mix design M25 Grade designed as per IS 10262:2009 & IS 456:2000
(FOR BANGAlORE REGION)
DESIGNED By: G.PRABHAKARAN M.TECh, QA/QC ENGINEER
Mix proportioning for a concrete of M25 grade is given in A·I to A-ll.
A·I STIPULATIONS FOR PROPORTIONING
a) Grade designation : M25
b) Type of cement : OPC 53 Grade conforming IS 12269
c) Maximum nominal size of aggregate : 20mm
d) Minimum cement content : 300 kg/m3 (IS 456:2000)
e) Maximum water-cement ratio : 0.50 (Table 5 of IS 456:2000)
f) Workability : 100-120mm slump
g) Exposure condition : Moderate (For Reinforced Concrete)
h) Method of concrete placing : Pumping
j) Degree of supervision : Good
k) Type of aggregate : Crushed Angular Aggregates
m) Maximum cement content : 340 kg/m3
n) Chemical admixture type : Super Plasticizer ECMAS HP 890
Mix design M30 Grade designed as per IS 10262:2009 & IS 456:2000
(FOR BANGAlORE REGION)
DESIGNED By: G.PRABHAKARAN M.TECh, QA/QC ENGINEER
Mix proportioning for a concrete of M30 grade is given in A·I to A-ll.
A·I STIPULATIONS FOR PROPORTIONING
a) Grade designation : M30
b) Type of cement : OPC 53 Grade conforming IS 12269
c) Maximum nominal size of aggregate : 20mm
d) Minimum cement content : 320 kg/m3 (IS 456:2000)
e) Maximum water-cement ratio : 0.45 (Table 5 of IS 456:2000)
f) Workability : 100-120mm slump
g) Exposure condition : Moderate (For Reinforced Concrete)
h) Method of concrete placing : Pumping
j) Degree of supervision : Good
k) Type of aggregate : Crushed Angular Aggregates
m) Maximum cement content : 360 kg/m3
n) Chemical admixture type : Super Plasticizer ECMAS HP 890
Mix design M35 Grade designed as per IS 10262:2009 & IS 456:2000
(FOR BANGAlORE REGION)
DESIGNED By: G.PRABHAKARAN M.TECh, QA/QC ENGINEER
Mix proportioning for a concrete of M35 grade is given in A·I to A-ll.
A·I STIPULATIONS FOR PROPORTIONING
a) Grade designation : M35
b) Type of cement : OPC 53 Grade conforming IS 12269
c) Maximum nominal size of aggregate : 20mm
d) Minimum cement content : 340 kg/m3 (IS 456:2000)
e) Maximum water-cement ratio : 0.45 (Table 5 of IS 456:2000)
f) Workability : 100-120mm slump
g) Exposure condition : Moderate (For Reinforced Concrete)
h) Method of concrete placing : Pumping
j) Degree of supervision : Good
k) Type of aggregate : Crushed Angular Aggregates
m) Maximum cement content : 390 kg/m3
n) Chemical admixture type : Super Plasticizer ECMAS HP 890
Mix design M40 Grade designed as per IS 10262:2009 & IS 456:2000
(FOR BANGAlORE REGION)
DESIGNED By: G.PRABHAKARAN M.TECh, QA/QC ENGINEER
Mix proportioning for a concrete of M40 grade is given in A·I to A-ll.
A·I STIPULATIONS FOR PROPORTIONING
a) Grade designation : M40
b) Type of cement : OPC 53 Grade conforming IS 12269
c) Maximum nominal size of aggregate : 20mm
d) Minimum cement content : 360 kg/m3 (IS 456:2000)
e) Maximum water-cement ratio : 0.40 (Table 5 of IS 456:2000)
f) Workability : 100-120mm slump
g) Exposure condition : Moderate (For Reinforced Concrete)
h) Method of concrete placing : Pumping
j) Degree of supervision : Good
k) Type of aggregate : Crushed Angular Aggregates
m) Maximum cement content : 420 kg/m3
n) Chemical admixture type : Super Plasticizer ECMAS HP 890