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What is the meaning of the defect liability period?
Sir As per Is -383 1970, the % of wt retained on 12.5mm must be nil. But when i conducted a sieve analysis of 10mm aggregate, i found out that about 1700 grams were retained on 12.5mm. Now as per ...
Now you can use the aggregate between sieve size 10mm retaining and passing from 12.5 mm.use locally available materials to reduce cost. Still, the mix design does not change but gives the desired result.
Now you can use the aggregate between sieve size 10mm retaining and passing from 12.5 mm.use locally available materials to reduce cost.
Still, the mix design does not change but gives the desired result.
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What is deadmen or tell-tales in excavation?
Basically in construction, deadmen refers to a heavy weight, typically a mass concrete block used to provide support or resistance to a load. These blocks are usually embedded firmly in soil, however some blocks may simply rest on the ground surface. A deadmen also referred to as a jacking lug.
Basically in construction, deadmen refers to a heavy weight, typically a mass concrete block used to provide support or resistance to a load. These blocks are usually embedded firmly in soil, however some blocks may simply rest on the ground surface.
A deadmen also referred to as a jacking lug.
See lessWhat is the difference between Ordinary Portland cement and Pozzolana Portland Cement? Which one is best for concrete works?
Particulars OPC PPC Name Ordinary Portland Cement Portland Pozzolana Cement IS Codes OPC 33 Grade Cement is IS: 269, for 43 Grade Cement IS: 8112 is used and for 53 Grade Cement IS: 12269 PPC IS 1489 (part 1 & 2) 1991 Ingredients & Manufacturing process Cement is made by heating limestone (CRead more
| Particulars | OPC | PPC |
| Name | Ordinary Portland Cement | Portland Pozzolana Cement |
| IS Codes | OPC 33 Grade Cement is IS: 269, for 43 Grade Cement IS: 8112 is used and for 53 Grade Cement IS: 12269 | PPC IS 1489 (part 1 & 2) 1991 |
| Ingredients & Manufacturing process | Cement is made by heating limestone (CaCO3 & clay) to 1450oC in a kiln & grounded with gypsum. | Pozzolana materials like fly ash, volcanic ash are blended to OPC @ 15%-35% by wt. |
| Environmental impact | Uses limestone clay & gypsum which are natural stones & emits CO2 during making. | Consumes industrial wastes such as fly ash, bf slag, etc. & is environment friendly. |
| Grades available | 33, 43, 53 Grades | Don’t have any grade but attains strength of 33 grade cement on 228 days curing. After that its strength gain slows down. |
| Cost per unit | Costly compared to PPC due to limestone | Cheaper bcoz limestone replaced by pozzolana |
| Sulphate resistance | Less durable in aggressive weather & sulphate attack & hence not preferred for marine structures, hydraulic structures, sewages pipes, etc. | Highly resistant to sulphate & used & preferred for marine structures, hydraulic structures, sewages pipes, etc. |
| Permeability & Durability | Low fineness, permeability is less | Higher fineness, higher permeability, result high durability. |
| Setting time | Initial setting time: 30mins
Final setting time: 280mins |
Initial setting time: 30mins
Final setting time: 600mins |
| Construction speed | Faster construction speed as it gains strength early. | Gains strength with time. |
| Fineness | OPC has finiteness of 225 sq.m/kg. It has lower fineness than PPC. So, it has higher permeability resulting lower durability. | PPC has finiteness of 300 sq.m/kg. It has higher fineness than OPC. So, it has lower permeability resulting in higher durability. |
| Heat of Hydration | It contains active salt hence more Heat of Hydration. Don’t have blended material & it gains 95% early strength in 7 days. | Blended cement with flyash or slag, etc. Low heat of hydration. Gains 75% strength in 7 days & 90% strength in 14 days. |
| Shrinkage cracks | Will be more due to high heat of hyudration | Less shrinkage cracks |
| Workability | Lower | Lower |
| Mass concrete | Not preferred | Preferred for mass concreting |
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What is fly ash silo ? Describe the design and detailing of Fly ash silo ?
Why are Concrete roads preferred over Asphalt Road?
The concrete roads are preferred over asphalt road because Concrete roads are long-lasting around the 20-40 year lifespan. It is also recycled after crushing into gravels, so It cost nothing or very little cost. It creates less environmental pollution than an asphalt road. High load and pressure resRead more
The concrete roads are preferred over asphalt road because Concrete roads are long-lasting around the 20-40 year lifespan.
It is also recycled after crushing into gravels, so It cost nothing or very little cost.
It creates less environmental pollution than an asphalt road.
High load and pressure resistance.
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What type of reinforcement used in prestressing concrete? Is it either the standard reinforcement used in conventional RCC structure, or is there any particular type or category of reinforcement for prestressing?
Hi, The prestressing steel used for prestressed concrete can take the form of Tendons Cables Wires – (Plain wire and Indented Wire) Strands –(Two-wire, three-wire and seven-wire strand) Bars The types of prestressing steel are: Cold Worked Prestressing steel Stress-relieving prestressing steel StraiRead more
Hi,
The prestressing steel used for prestressed concrete can take the form of
The types of prestressing steel are:
Read More: Specifications of Prestressing Steel in Prestressed Concrete
Difference between Reinforcing Steel and Prestressing Steel
Both R.C.C and Prestressed Concrete employs steel bars or wires in order to sustain tension. But both the types of concrete make use of different steel.
The steel used by R.C.C concrete can be:
The steel used in Prestressed Concrete are wires, strands, solid bars as mentioned above. Prestressed concrete uses high tensile strength steel that is manufactured by increasing the carbon content in steel compared to ordinary mild steel used in R.C.C.
In prestressed concrete, the steel used is tensioned or prestressed. This results in loss of prestress in a range of about 20%. The use of mild steel bars or HYSD bars bring a greater loss than this value. Hence, it is necessary to have high strength tensile bars for prestressed concrete.
Also Read: What is Steel Reinforcement? Types and Properties of Steel Reinforcement?
Regards
See lessWhat is the percentage of stone dust that can be added along with fine aggregate in different designs of concrete (Say M-20)? What is the difference between the concrete with and without dust? Does adding dust helps in increasing/decreasing strength?
Difference between concrete with and without dust: The compressive strength of concrete will increase after adding dust in it. Various research shows maximum compressive strength at 60% dust used in concrete. When we talk about workability then dust concrete has low workability as compared to no dusRead more
The compressive strength of concrete will increase after adding dust in it.
Various research shows maximum compressive strength at 60% dust used in concrete.
When we talk about workability then dust concrete has low workability as compared to no dust concrete.
I hope so you found my answer more helpful to you.
Thank You.
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Emmyvin
Defect Liability period is a particular amount of time given to the contractor after the completion of a project to check if the project is delivered in good shape, whereby if any defects be detected, the contractor is to fix the defect for free during the defect liability period.
Defect Liability period is a particular amount of time given to the contractor after the completion of a project to check if the project is delivered in good shape, whereby if any defects be detected, the contractor is to fix the defect for free during the defect liability period.
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