The Alccofine 1203 product is a specially processed slag containing a high percentage of glass, resulting from a controlled granulation process. An enhanced hydration process is a result of both the latent hydraulic property and pozzolanic reactivity. With the addition of Alccofine, the paste component will pack more densely. Therefore, concrete at any age will be stronger and more durable due to a reduction in water demand.

Figure 1 SEM image and chemical composition of Cement

 

Figure 2 SEM image and chemical composition of Alccofine

 

2.    Experimental Investigation

Mix design was performed in accordance with IS 10262: 2019 code for trail mix for M40 grade. Alccofine was used as a substitute for cement at percentages of 0, 5%, 10%, 15%, and 20% for concrete of grade M40. In addition to cement and fine aggregate, coarse aggregate and water were also used in the mix design. Moreover, Alccofine 1203 increases concrete's strength, thereby providing the concrete with more workability and other advantages.

 

2.1. Cement

used for all specimens was ordinary Portland cement of 53 grade confirming to IS: 12269:2013 was used. The cement used for all specimens was ordinary Portland cement grade 53 that complied with IS: 12269:2013.

 

2.2. Alccofine 1203

In comparison to its chemical composition and physical characteristics listed below, ALCCOFINE 1203 has a unique chemical composition primarily composed of CaO 30-34% and SiO₂ 30-36%. In terms of particle size distribution, the product is physically unique.

 

Figure 3 Cement and Alccofine

 

Table 1 Elemental compositions of cement and Alccofine by EDAX
Compounds and elements	Compound formula	Cement (%)	Alccofine (%)	Composition of cement as per IS 12269-2013 (%)
Calcium	CaO	72.82	39.17	60-67
Silicon	SiO2	14.64	29.22	17-25
Iron	FeO	3.62	-	0.5-6
Aluminium	Al2O3	4.78	20.19	03-Aug
Sulphur	SO3	2.32	-	01-Mar
Magnesium	MgO	1.14	6.62	0.1-4
Potassium	K2O	0.4	0.25	0.1-1
Sodium	Na2O	0.22	0.06	0.1-1
Titanium	TiO2	0.07	0.24	-

 

2.3. Fine Aggregate

The fine aggregate is as per the IS 383-1970 code conforming that is coming under ZONE II. The fine aggregate is in accordance with the IS 383-1970 code, which falls under Zone II.

 

2.4. Coarse Aggregate

The coarse aggregate conforming to IS 383-1970 was used. In this project, coarse aggregates that conform to IS: 383-1970 were used. Aggregates ranging in size from 12 to 20 mm were used.

Figure 4 Fine and coarse aggregates used in experimentation

 

Table 2 Mix proportions of M40 grade concrete /cum
	0%	5%	10%	15%	20%
Cement	367	399	378	357	336
AL	0	21	42	63	84
Water	148	152	152	152	152
F.A.	767	646.6	646.6	616	646.6
C.A.	1140	1322	1322	1308	1322
SP	3.7	4.2	34.2	4.2	3.4.2

 

2.5. Water

Potable water was used to mix concrete and cure specimens.

 

2.6. Concrete

The cement used is Portland Cement 53 grade. Tests are conducted on cement based on the procedures prescribed in IS: 1489. Maximum size of 20mm for aggregate and a size range of 0 to 4.75mm for fine aggregate is required. In order for the concrete to stabilize its own properties, such as compressive strength, it needs to be allowed to cure in real environmental conditions for about 28 days. A concrete cube (100mm x 100mm x 100mm) is loaded under axial compression to test its strength.

Figure 5 Casting of concrete cubes

 

Figure 6 Cubes allowed for curing in curing tanks

 

2.7. Compressive Strength

A material's capacity to withstand pressure that tends to reduce its size is its compressive strength

 

Figure 7 Compression testing machine (C.T.M.)

 

3.    Results and discussion

In this study, the compressive strength of concrete mixed at various proportions will be determined. Graphs and bar charts are used to present the test results. Figure 5 shows various mix proportions of concrete and the results obtained in terms of compressive strength.

Figure 8 Compressive Strength for M40 Grade Mix

 

Figure 7 and Figure 8 illustrate the compressive strength values of Alccofine dosages in concrete after 7 and 28 days of curing. With increasing curing durations and extended hydration periods, the compressive strength improves with age. In the initial mixes containing only Alccofine, the maximum strength was observed for 15%.

Figure 9 Microscopic images of M40 grade concrete at 15% optimum dosage of Alccofine

 

For M40 grade concrete with 15%, Alccofine replacement, it exhibited a maximum compressive strength of 40.62mpa and 57.65mpa after 7 days and 28 days respectively.

For this mix, from 7 days to 28 days, there was an increase of 29.54%. At 7 days and 28 days, the compressive strength gain compared to the conventional mix is 17.06% and 16.23% respectively. At 7 days, the compressive strength of 10% mix and 20% mix is lower than that of 15% mix, by 10.08% and 6.34% respectively. At 28 days, the compressive strength of 10% mix and 20% mix is lower than that of 15% mix, by 7.16% and 1.68% respectively. Therefore, it is observed that the 15% mix shows higher strength than all other mixes.

 

4.    Conclusions

According to the experimental results, the following conclusions can be drawn:

·        Compared to other mixes (0%, 5%, 10% and 20%), 15% replacement mix gives better compressive strength. Concrete's compressive strength increases when alccofine is added.

·        Increasing the level of alccofine above 15% in a mix will only act as a filler material, while its strength will gradually decrease over time.

·        The test results indicate that weight loss decreases as alccofine addition increases. However, there is a limitation that strength will decrease with increased alccofine concentration.

·        We conclude that alccofine 1203 was a good cementitious material replacement to the extent of 15%. Furthermore, its durability is also excellent.

·        Furthermore, further research is needed to standardize the use of alccofine in concrete.

·        The concrete shows denser and homogeneous microstructure for concrete containing 15% alccofine. Due to presence of silica and calcium in Alccofine, there was extra formation of CSH gel which is clearly shown in the microstructure.

 

REFERENCES

A.C. Saoji and M.S. Pawar (2013) Effect of Alccofine on Self Compacting Concrete. The international journal of engineering and science, Vol.2, 5-9.

Abhijisinh (2009) "Utilization of pond fly ash as à partial replacement in fine aggregate with using fine fly ash and Alccofine in HSC- Hards concrete properties". International Journal of Engineering Development and Research, Vol.4, 74-77.

Ali Bashah (2006). Effect of silica fume to the strength and permeability of high-performance ground granulated blast furnace slag concrete. University Technology Malaysia, pp.1-68.

Aponte F, M Barra, and Vazquez (2012) Durability and cementing efficiency of fly ash in concretes. Construction and Building Material, Vol.30, 537-546. Retrieved from  https://doi.org/10.1016/j.conbuildmat.2011.12.026

B.K. Shah and Suthar Sunil (2013). Strength development of high strength concrete containing Alccofine and fly-ash. Indian journal of research, Vol.2, 102-104. Retrieved from https://doi.org/10.15373/22501991/MAR2013/38

Bureau of Indian Standards, IS : 456 - 2000 Code of practice for Plain and Reinforced Concrete (third edition) New Delhi, India.

Bureau of Indian Standards, IS : 10262-2009 Concrete mix proportioning (First revision), New Delhi, India.

Bureau of Indian Standards, IS : 12269 - 2013 Specification for 53 grades ordinary Portland cement (first revision) New Delhi, India.

Bureau of Indian Standards, IS : 383 - 1970 Specification for fine and coarse aggregates from natural sources of concrete (Second revision) Jan 2007. New Delhi, India.

Bureau of Indian Standards, IS : 516 - 1959 Methods of tests for strength of concrete.New Delhi, India.

Darren Lim, Sabet Divsholi, Da Xu, Susanto Teng, Kondraivendhan (2011). Effect of ultrafine slag replacement on durability and mechanical properties of high strength concrete. 36th Conference of Our World in Concrete & Structures, Nanyang Technological University, 14-16.

Dr. Mohd.Hamraj (2014) Experimental Study On Binary blended high strength steel fiber reinforced concrete using Alccofine as mineral admixture, International journal of science and technology, Vol.2, 56-62.

F.Gameiro, J.de Brito and D.Correia da silva (2014) Durability performance of structural concrete containing fine aggregates from waste generated by the marble quarrying industry. Engineering Structures, Vol.59, 654-662. Retrieved from https://doi.org/10.1016/j.engstruct.2013.11.026

M.A. Jamnu, Siddharth P Upadhyay, (2014) Effect on compressive strength of high-performance concrete incorporating Alccofine and fly ash. Journal On International Academic Research For Multidisciplinary, Vol.2 125-130.

Saud Otaibi (2004) Durability related properties of alkali-activated slag concrete. 29th Conference of our world in concrete & structures, Kuwait Institute for Scientific Research, Singapore : 25 -26 August.

Swaroop, Venkateswara K and Kodandarama Rao (2013). Durability studies on concrete with fly ash and GGBS, International Journal Of Engineering Research and Applications, Vol.3, pp 285-289.