An Investigation of High-Performance Self Compacting Concrete under Flexural Loading

To shorten construction period, to assure compaction in the structure especially in confined zones where vibrating compaction is difficult and to eliminate noise due to vibration effective especially at concrete products plants SCC is developed in practice. Also, SCC is applied to tunnel lining for preventing the cold joint Self -compacting concrete has been used. Currently, the main reasons for the employment of self-compacting concrete can be summarized as follows: developing alternate binders that are environment-friendly and contribute to sustainable management. The properties of SCC in fresh concrete stage cost reduced time and substantial effective construction expertise in Special concrete of High-Performance Self Compacting Concrete (HPSCC) properties, the present work as major aspects like Effect of fibers with Fly ash on Fresh concrete properties and Behavior of polypropylene fibers Specimens under split tensile & Flexural loading. The first parts of the work have been focused on the effect of polypropylene fibers on Fresh and harden concrete of Ultimate Strength with replacement of varying Polypropylene fibers by 0% to 1.5% at the interval of 0.5 and next part of the work focusing the behavior of fiber under Flexural loading. The results obtained from this work are expected to be useful in determining behavior of SCC with polypropylene fiber Specimens. This will help the designing SCC specimens to resist Flexural loading.


Introduction
High Performance Self Compacting Concrete (HPSCC) is the one which ability to Flow, good viscosity, segregation resistance and passing ability. The supplementary cementitious materials like fly ash are used to improve the alkali-aggregate reactivity with the correct dosage of superplastizers mix. Superplastizers are used to avoid segregation in concrete mix and have a good and high slump. Some earlier research shows that viscosity modifying admixture to enhance stability and rheological properties improve by fly ash. Supplementary Cementitious materials also react differently with different cement. Heat of hydration of the cement by using fly ash in high performance SCC reduces cracking of concrete. In this work up to 60% of the Portland cement is replaced by fly ash. The application of the high-performance SCC is wider range used to constructions area where required high strength and particular property of concrete is improved.
Fibers like glass, nylon, coir, steel, asbestos and polypropylene(PP) etc. have been used in the previous. Out of these polypropylene fibers best performance to enhanced the properties of flexural strength [1,2]. Steel fibers also better improve the toughness and flexural strength, but it damages by corrosion and increased densities are the one of the drawbacks. Due to this polypropylene fiber is used in this study [3].
The workability of the High-Performance SCC is excellent because of using fly ash in this present work. The outlines of the article evaluating the Performance of High-Performance SCC in both fresh and harden state characteristics enhance the performance [4,5]. The behaviours of High-performance SCC in flexure are study in the present work to know the behaviours of Fly ash and fiber combination in the current situation in the concrete industries.

Earlier Works
From the review of earlier investigations related to mechanical properties of SCC with fly ash under Flexural loading with increased performance and function having been reported [6,7] and some results show the behaviours of elements have been tabulated on the researchers of such studies. No information has been available on the response of High-performance SCC with fly ash & polypropylene elements subjected to Flexural loading.

Materials
The following materials are used, Fly ash iii Fine aggregate iv Coarse Aggregate v Polypropylene vi Water i Cement: Ordinary Portland cement conforming to IS: 12269-2013, which was stored in a cool and dry place, was used [8,9] and physical properties of cement shown in Table 1.
ii Fly ash: The fly ash Class F (Type-II) used to replace cement was obtained from Thermal power plant, Raichur and tested [10] the properties shown in Table 2.
iii Fine aggregate: M-Sand used in the High-performance SCC is taken from near quarry. This M-sand is totally free from all impurity and organic matters and tested [11], the properties shown in Table 3. iv Coarse aggregate: 20mm down aggregate used in the High-Performance SCC is taken from near quarry. This aggregate is totally free from surface moisture and all impurity with gradation and tested [12] and their properties shown in Table 4.  The mix design of M40 grade concrete with water/cement ratio 0.4, Mix contents of varying fibers Polypropylene with a mixing ratio of 0% to 1.5% with intervals of 0.5% by volume were used, Super plasticizer 0.8%, Portable cement 425 (kg /m 3 ), M-sand and coarse aggregate 705 kg /m 3 and 1090 kg /m 3 were also used for Slump of 75mm.The design mix proportions of Concrete were determined. The materials proportions of the High-performance SCC with addition of fly ash and Polypropylene fibers with fresh concrete properties (EFNARC) are shown in Table 5-8 and tested of harden concrete according to codal provision [13,14].

Results and Discussions a). Compressive Strength test (CST)
The compressive strength test (CST) for normal SCC and Fly ash Replace with varies %of High-performance SCC for 28 days were conducted and shown in figure 1, The results show Compression Strength tests PM 0-PM1.5.

Conclusion
In this investigation of the present work, the following points to be noticed based on Experimental work, 1. From this investigation shows that the addition of polypropylene fibers in high performance SCC gives homogeneous and mix of cohesive but decreases marginal workability. 2. The fresh properties of High-performance SCC concrete with fly ash satisfied the codal provisions recommendations with value. 3. The addition of fibers to the high-performance SCC concrete is increases the mechanical properties at 1 % addition of polypropylene fibers attains the maximum strength. 4. From this study high performance SCC produced with 40% of fly ash with 1% of fiber addition. 5. Replacement of fly ash of class-F with Cement at a ratio of 40 % is increases the hardened properties. 6. The addition 40% replacement of fly ash attains maximum compressive strength of 52.8 N/mm 2 , Split tensile strength test of 7.2 N/mm 2 & flexural strength of 9.85 N/mm 2