What are other alternatives for aggregates in concrete?
- Expanded Polystrene(EPS): EPS balls are used as an aggregate instead of the crushed stone that is used in regular concrete, it known as EPScrete, EPS concrete or lightweight concrete. It has been used as road bedding, in soil or geo-stabilization projects and as sub-grading for railroad trackage.
It is created by using small lightweight Styrofoam or EPS balls as an aggregate instead of the crushed stone that is used in regular concrete. It is not as strong as stone-based concrete mixes, but has other advantages such as increased thermal and sound insulation properties, easy shaping and formed by hand with sculpturing and construction tools. EPS concrete combines the construction ease of concrete with the thermal and hydro insulation properties of EPS and can be used for a very wide range of application where lighter loads or thermal insulation or both are desired.
- Expanded polystyrene concrete
- Crushed rubber: When vehicles tires reach the end of their usable life, they can still find some use as a replacement for course aggregate in concrete mixes. "Crumb rubber" is crushed form of car or truck tires that are ground up between the sizes of 3 - 10 mm. This mix has very poor compressive strength due to its high air content. It is believed that when this rubber is mixed in with the concrete air becomes trapped in with it. One benefit to the addition of this alternative is the rubber keeps the concrete from shattering in failure.
- Workability and mechanical properties of crumb-rubber concrete
- Glass: Crushed glass can also be used as an alternative to aggregate in concrete and this type of concrete is known as Glasscrete. As a construction material, the glass offers several advantages that
could be exploited in the concrete industry. Some of these advantageous properties are given below:
- The very significant hardness of glass gives the glasscrete an abrasion resistance that very few natural stone aggregates can match.
- Because glass aggregate has basically zero water absorption, it improves the flow properties of fresh concrete so that a reduction in water content can be obtained even without the use of water reducing admixtures.
- The high chemical resistance of the glass to acidic solutions makes it suitable be applied to cases when the exposure to those chemicals is expected.
- The novel colors and pellicular reflective nature of glass aggregates give it special light reflections that couldn’t be obtained with regular natural aggregate, make it very attractive for decorative concrete applications.
- Because it is readily available to some extent, it could be considered as a low cost material.
- High Density Polyethene (HDPE):High-density polyethylene can be added to concrete as a replacement for course aggregate. But as the name implies, the material is too ductile at full strength to support structural loads at 2500psi. One benefit to this material is its measurable qualities in holding heat within buildings.
- Paper Pulp: Paperpulp is mixed with portland cement and white lime in the ratio 4 : 1 : 0.5 to form an entirely different type of concrete known as Papercrete. It is very weak and hence not used for structural purposes.