Precast Concrete Construction
Within the mid-nineties, I had been heading a civil design department for almost any large EPC contractor in East Asia. We’d received a purchase to produce a paper plant.
The main building within the paper plant may be the paper machine building. An average paper machine building is all about 300 m extended. The dwelling typically has two floors, one at venture out, the other at roughly 7.5 m level. The paper machine is included in the basis that isn’t attached to the building. Readily stored away accessible inside the machine hall at 7.50 m level. This building houses other complex and machinery and possesses very stringent needs regarding quality, structural design and stability. The very best expires high plus a handful of in the regions of this building are more likely to temperatures between 50 to 60 C. A large overhead crane straddles the upstairs machine hall. The differential settlement within the paper machine foundation should be under one mm and overall settlement anytime under 1.25 mm. This building, wonderful its components along with the equipment foundations, often takes 18 a few days to produce.
Our md will be a cutting-edge man in addition to searched for ideas to accelerate construction. Eventually, he known as me to his office and proven me articles narrating of the company in the united states that have developed methods for produce a paper machine building using pre cast elements. This paper machine building was transported in an increasing length of 6 a few days, pointed out the data. We hired the united states .states company as our consultants and they also did the engineering using our engineers within our office. We built our paper machine building each year cutting lower time by about six a few days. It absolutely was despite a delay of roughly three a few days because of the learning curve along with the time needed for developing a precast plant.
Thus started my twenty-couple of years extended link to pre-cast concrete. My old company has created several large industrial plants along with other structures after that.
In a number of first world countries pre cast elements for bridges, culverts are really standardized. Pre-casting units can be found near major towns offering these components for that construction sites. This not just cuts lower round the construction time nevertheless the design time when you uses standard elements whose characteristics are known.
You will find variations within the precast concrete construction for example tilt up construction, module fitments etc.
I’ve frequently wondered why India, while using much construction required for the all of the sectors of construction, hasn’t recognized this method. Aside from other difficulties like dependence on repetition, unfriendly taxation, reliance upon transport or lifting machinery etc., For me our engineers haven’t given a considerable considered to developing this method.
I must share numerous my learnings.
- Planning is important: The dwelling to obtain constructed from precast elements should be damaged reduced elements, within the pre-determined configuration. It’s just like making the products of the jigsaw puzzle whenever develop will in the completed puzzle. It’s really a mix of standard and non-standard pieces.
- God reaches details: Each element thus planned should be detailed to match all of the elements on its sides along with the embedment needed for utilities.
- Design the big event and Construct the look: Normal structural engineering practice of designing the very best product and departing the “How?” for that construction personnel, doesn’t be employed in precast. The structural engineer must stay involved while pre casting, erection and.
To get affordable my understanding, IS codes don’t have specific provisions for pre cast structures unlike ACI or BS codes. A few in the clauses in ACI may be substituted by provisions in their extra publications. Such provisions need to be applied judiciously transporting out an effective assessment within the measures within the service existence within the element. A foremost expert on pre-casting once pointed out “Applying provisions of R.C.C code to pre-casting may be like playing tennis obtaining a baseball bat”
The structural the idea of a precast element is carried out for many stages of at the begining of existence. Multiple level checks are crucial to the element lies, more checks are crucial it could be a pre-stressed element with partial united nations-connecting of tendons.
- Joints might cause headaches: Resolving and configuring some pot between precast elements is unquestionably a hard task. It might be a heuristic method to balance relating to the structural requirement, functionality regarding fundamental consideration as water tightness, and the way big the weather the component in consideration is attached. Joints need to be built how they are really envisaged.