STRENGTH CHARACTERISTICS OF MULTI-FIBER REINFORCED CONCRETE WITH MINERAL ADMIXTURES

Concrete is one of the most commonly and widely adopted material for construction. Cement is used as primary binder material to produce Concrete. However, every tonne of Cement production releases one tonne of greenhouse gases which results in global warming; due to continuous and ever increased usage of Cement and natural sand are causing uncontrollable global warming and depletion of natural resources respectively year by year. This tendency needs to be retarded if not arrested, by developing a comprehensive approach to use more and more pozzolanic mineral admixtures and manufactured sand (M-Sand) in Concrete. In this study on fiber reinforced concrete (with steel fiber @ 1% of binder), Ordinary Portland Cement (OPC) is replaced up to 50% with Fly Ash and Ground Granulated Blast-Furnace slag (GGBS) for M30 grade of Concrete. Mechanical properties like compressive strength and split tensile strength at 7 days and 28day age are tested. Additionally, durability tests like water absorption and sorptivity tests are conducted after 28days of curing. The test results indicated that workability was increased and there was no significant improvement in durability properties on increasing the percentage of OPC replacement. However, 30% of OPC replacement is found to be optimum for strength criteria

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Nanomodification of Lightweight Fiber Reinforced Concrete with Micro Silica and Its Influence on the Constructive Quality Coefficient

Materials ◽

10.3390/ma14237347 ◽

2021 ◽

Vol 14 (23) ◽

pp. 7347

Author(s):

Evgenii M. Shcherban’ ◽

Sergey A. Stel’makh ◽

Alexey Beskopylny ◽

Levon R. Mailyan ◽

Besarion Meskhi ◽

...

Keyword(s):

Reinforced Concrete ◽

Fiber Reinforced Concrete ◽

Strength Characteristics ◽

Structural Quality ◽

Fiber Reinforced ◽

Modifying Additives ◽

Quality Coefficient ◽

Design Characteristics ◽

Micro Silica ◽

Modifying Additive

A hypothesis was put forward that a nano-modifying additive of micro silica, which had a beneficial effect on achieving a perfect structure of heavy concrete, can also be effectively used in lightweight fiber-reinforced concrete. The nano-modifying additives of micro silica application in manufacturing lightweight fiber reinforced concrete products and structures can significantly enchain their strength characteristics without increasing their mass and consequently improve their design characteristics. The purpose of the work was to increase the structural quality coefficients for all types of strengths of lightweight fiber-reinforced concrete due to its modification with micro silica. The effect of nano-modifying additives of micro silica on the strength characteristics of lightweight fiber reinforced concrete was studied. The optimal amount of micro silica addition was experimentally confirmed and established of 10% of the cement mass. The coefficients of constructive quality for all experimentally determined strength characteristics of lightweight fiber-reinforced concrete modified with micro silica additives were calculated. The coefficient of constructive quality for tensile strength in bending of lightweight fiber reinforced concrete with additives was two and a half times higher than that of heavy concrete without additives and up to 37% higher than that of lightweight fiber-reinforced concrete without additives.

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