Confirms to IS 9142 PART 2 - ARTIFICIAL LIGHTWEIGHT AGGREGATES FOR CONCRETE
Concrete is one of the most versatile and frequently used materials in construction and has been so since Roman times. India being a developing country will require concrete in huge proportions.
Approximately three fourth of the volume of concrete is occupied by Coarse and Fine aggregate (sand).
These Coarse aggregates are presently excavation from large mountains and crushed into the different sizes and similarly fine aggregates are mined from the river bed which has long term environmental impact. In order to augment our social responsibility towards preserving Earth to use of alternate Eco-friendly Coarse aggregates in concrete like Sintered Aggregates (SINTAGG).
SINTAGG is commonly known worldwide by its generic name i.e. Low Density Aggregates (SINTAGG) / Light Weight Aggregate(LWA) / Sintered fly aggregate and is in wide precedence in UK,USA and the Middle East since last 3-4 decades. SINTAGG is supplied by LITAGG Industries Pvt Ltd (LIPL) , Ahmedabad , Gujarat
SINTAGG is the only known product in the world to possess the maximum capacity to utilize of Fly Ash as core raw material. It contributes manifold to safe guard the environmental conservation by reducing pollution created by quarrying of mines to extract conventional stone chips and also by reducing the atmospheric hazards associated with dumping of fly ash in ash ponds and low land fillings.
It also contributes to the concept of a greener tomorrow and adheres to the 3R's of waste management i.e.
Reduce, Reuse and Recycle.
Apart from these environmental contributions it is an advanced replacement of natural aggregate/granite stone chips commonly used for concrete applications including PCC and RCC as well.
It is very much beneficial to the new age construction industry because of its low bulk density, low thermal conductivity, internal curing, better compaction, easy pumpable, usage of less steel reinforcement etc. It has been used to make lightweight concretes and the reduction in concrete density has a significant effect on the dead load of the structure. Consequently foundation sizes can be reduced, additional floors can be constructed, thinner section beams and columns can be used etc.
Manufacturing Process:- The raw materials are Fly Ash which is a waste material from the coal based thermal power plant, Powder Coal and Water. It is made by pelletizing the fly ash by adding adequate quantity of powder coal and water in a specially designed disc pelletizing pans, rounded pellets are formed by adjusting the parameters of palletized, called as “Green Pellet”. The green pellets are then heated on a sinter strand to temperature of around 1100ºC and similarly an adequate amount of suction pressure. The result is a hard, honeycombed structure of interconnecting voids within the aggregate. The particles formed are rounded in shape and range in size from 16mm down to fines. These sintered aggregate are subsequently screened as per required sizes and is ready for use as per the requirement.
Physical & Chemical Properties:- The performance of concrete are dependent on the properties of the aggregate themselves. As three-fourth of the volume of concrete occupied by aggregate so, the performance of concrete depends on the quality of aggregate used. In general, an aggregate to be used in concrete must be clean, hard, strong, proper shaped and well graded. When determining the strength of normal concrete, most concrete aggregate are several times stronger than the other components in concrete. Not only may the aggregate limit the strength of concrete, as aggregate with undesirable properties cannot produce strong concrete but the properties of aggregate greatly affect the durability and performance of concrete.
Size Gradation:- Size distribution of aggregate plays an important role because, if all the particles of an aggregate are of uniform size, the compacted mass will contain more voids and it will affect the strength of the concrete. The aggregate should be such that the smaller particles fill the voids between the larger particles, in general the aggregate should well graded for which produce better bond and more strong. - The size distribution of SINTAGG 8-16mm and SINTAGG 4-8 mm confirms to the grading requirement for lightweight aggregate for structural concrete for coarse aggregate Strength:- Crushing Value, Impact Value, Abrasion Value as per IS 9142 part 2 and Crushing Resistance .
The Crushing Value of SINTAGG8-16 and SINTAGG 4-8 are 43% and 32% respectively and confirms to the IS 383: for the coarse aggregate used for concrete other than for wearing surface.
Impact Value:- The Impact Value of SINTAGG 8-16 is 36 % it confirms to the IS 383: for the coarse aggregate used for concrete other than for wearing surface.
Abrasion Value:- The Abrasion Value of SINTAGG 8-16 and SINTAGG4-8 are 33% and 32% respectively and confirms to the IS 383: for the coarse aggregate used for concrete other than for wearing surface.
Crushing Resistance :- The Crushing Resistance of SINTAGG 8-16 and SINTAGG4-8 are 7 Mpa and 8 Mpa respectively.
Bulk Density:- The Bulk Density of aggregate is defined as the mass of the material is required to fill in a given container in a unit volume it depends on the packing of aggregates i.e loosely or in compact. - The oven dry loose bulk density of SINTAGG 8-16 and SINTAGG 4-8 are 810 Kg/m³ and 830 Kg/m³
Water Absorption:- The water absorbed by the dry aggregate when immersed in water for 24 hour. The aggregate water absorption is very important for concrete mix design.The 24 hour water absorption of SINTAGG 8-16 and SINTAGG 4-8 are 14 % and 13% respectively. As per standards the 24 hour absorption of lightweight aggregate ranges from 5 to 20 percent by mass of dry aggregate but, for good quality aggregate for use in structural concrete, it is usually not more than 15 percent.
Specific Gravity:- The specific gravity of an aggregate is defined as the ratio of the mass of solid in a given volume of sample to the mass of an equal volume of water at the same temperature. This is required during concrete mix design. - The specific gravity of SINTAGG 8-16 and SINTAGG 4-8 are 1.5 and 1.51 respectively in dry condition.
Deleterious Materials and Organic Impurities Content:- The materials whose presence may adversely affect the strength, workability and long term performance of concrete. These are considered undesirable as constituent because of their intrinsic weakness, softness, fineness or other physical or chemical characteristics harmful to the concrete behavior.
The deleterious materials and organic impurities content result of SINTAGG8-16mm and SINTAGG4-8 mm are 0.36% and 0.33 % respectively and confirms to the IS-383 requirement of maximum 5%.
Alkali Aggregate Reaction :- The reaction can be disruptive and manifest itself as cracking in concrete which directly affect to the strength of the concrete and eventually failure of concrete structure. - The alkali reactivity test result for both fraction of SINTAGG is Innocuous as per ASTM C 1260 and IS 383. Soundness :- The soundness indicates the ability of the aggregate to resist excessive changes in volume due to changes in environmental conditions and by the chemical reactions between the aggregate and the alkalis in cement, result in deterioration of the concrete. - The soundness of SINTAGG 8-16mm and 4-8 mm are 1.64% and 0.66% and confirm to the IS 383 requirement of maximum 12%.
Loss on Ignition:- Loss on ignition indicates the present of unborn carbon in the aggregate. Excessive presence of carbon in aggregate can deteriorate the concrete. - The loss on ignition of SINTAGG 8-16mm and 4-8 mm are 2.15 % and 2.02 % where requirement of maximum 5% as per standards.
Sulphate (So3):- Sulphate is harmful to concrete which shall yield in the homogeneous nature of the concrete getting deteriorated subsequently, it may hamper the concrete by manifold cascading effects like Weak Cohesiveness, lagging behind in attaining strength, durability etc.
The sulphate (So3) present in SINTAGG8-16 is 0.1% and is very less.
As a secondary aggregate manufactured from the by-products of an industrial process, not only diverts waste from landfill but also reduces demand for natural quarried material. From the sustainability point of view SINTAGG has distinct advantages over natural materials. Low Density Aggregate is an advanced replacement of natural aggregate/granite stone chips commonly used for all sort of concrete applications. Apart from its manifold environmental contributions it is very much beneficial to the new age construction industry because of its low bulk density, low thermal conductivity, internal curing, better compaction, easy pumpability, usage of less steel reinforcement etc. Lighter in weight than normal concrete, but as strong, structural light weight concrete made with SINTAGG. This allows for long cantilevers, slimmer general sections and reduced foundations size. Moreover SINTAGG can reduce the dead load of the concrete structure by 20-23% because of it is comparatively lighter in weight. SINTAGG can be used in all sort of concrete applications including PCC and RCC as well. SINTAGG is best suitable to be applied in the construction of Green buildings, Precast Structures, Landscaping, Floor and Roof Screed, Arrester Bed, Filter madia and as a filling material. It is highly essential for tall rise building where every addion load play a vital role for the building, moreover there is the potential additional benefit of reducing project cost. .