Concrete with plastic aggregates at normal curing gives strength where as concrte cured at elevated temperature gives strength or while curing the ingredients in the plastic react with cement and other natural resources and there by increase or reduce the strength of concrete.
It depends on the thermal stability of the polymer. Some polymers may melt at the temperatures the concrete is submitted during thermal curing. Even without melting, mechanical properties of the polymers may be influenced by elevated temperatures (normally they lose stiffness and strength). Check the parameters of the type of plastic aggregate you use.
It is less likely that polymers react with the cement or hydration products.
If polymer is exposed to elevated temperature at some point it melts and fills the pores in the concrete, after filling whether the concrete will be durable?
It is an interesting question. I think this filling will tend to be inhomogenous since melted polymers will pour downwards. There are some more effective ways to seal concrete with polymers in order to enhance durability.
Nerertheless it worths trying it (it can be interesting from the point of view of plastic recycling). I recommend to use plastic aggregate as fine as possible in order to avoid the creation of large voids inside of concrete.
it depends on the time of exposure to elevated temperature and degree of heat and methods of cooling used . in general concrete after 400 c began to lose its strength.
It's a better thought of filling the voids by treating plastic at elevated temperature. But when the plastic melts and diffuse into the pores, a cavity gets created in its initial position in the matrix. This in turn makes the system weak and in action of load, the cavity might cause the initial plane of failure.
The surface characteristics of plastic is so smooth that sufficient interlocking of the aggregate and matrix may not get attained. Hence it is advisable to roughen the surface of the plastic aggregate prior to usage. Plastic is inert and won't react with any of the ingredients of concrete. Hence curing at elevated temperatures is not recommended since it can only weaken the matrix by destabilising the plastic aggregate.
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