Feasibility Study on Use of Aluminum Waste and Industrial By-products in Paver Blocks (An ISRO RESPOND Project)

Abstract

Paver Blocks are newly developed product as the substitute for conventional rigid and flexible pavements. Paver Blocks are available with various shapes as per the codal requirements. OPC paver blocks are conventional paver blocks available in the market. The compressive strength of commercially available paver blocks varies from 30 MPa to 50 MPa based on their application. Industries mainly produce useful materials, however along with such useful materials, different byproducts are also produced in billion tons. The dumping of these industrial byproducts is a major issue with continuous increase in industrial development. For sustainable development, it is essential to reduce the fast diminishing natural resources. These industrial by-products can be used as an alternative of natural resources. Similarly, large amount of remains of Aluminum AL6061-T6 is produced at SAC-ISRO workshops during manufacturing of various equipment and machineries. This Aluminum AL6061-T6 can be used as an additional ingredient in concrete paver blocks. In this study, feasibility of addition of Aluminum AL6061-T6 produced in SAC-ISRO, Ahmedabad workshop is used in concrete paver blocks made with different industrial by-products. The present investigation is started by collecting the basic information related to commercially available paver blocks like size, shape, constituents materials, compressive strength and cost of paver blocks etc. from different paver blocks manufacturers of Gujarat. Different industrial by-products have been selected and tried to use for the production of concrete paver blocks. Fly ash, different types of slags, marble powder, etc. are used as a partial replacement of cement for concrete paver blocks. Waste foundry sand and recycled aggregates are chosen for partial replacement of sand and full replacement of aggregates, respectively for the paver blocks. Appropriate dosage for all the materials is evaluating by preliminary investigation on concrete paver blocks. Effect of addition of aluminum AL6061-T6 is also investigated for various types of concrete paver blocks. The zig-zag type of paver blocks of 60mm thickness as per IS provisions have been prepared. Mechanical properties of concrete paver blocks are evaluated which included compressive strength, ultimate breaking load, flexure strength, split tensile strength and water absorption. Paver blocks made using each mix are recommended for best suitable traffic category applications as per IS recommendation. Guidelines regarding the mix design of concrete paver blocks is not available in literature. Requirement of minimum binder content and w/b ratio for respective traffic category application is not available for concrete paver blocks. Based on the results of the investigations, fly ash based and GGBS based concrete mixes with 1% dosage of aluminum AL6061-T6 have been identified for investigation related to development of mix design guidelines. For both mixes, effect of variation in binder content and w/b ratio have been explored. Based on the results of compressive strength, ultimate breaking load and flexure strength, paver blocks are recommended for suitable traffic application. Hence, for each category of traffic applications, minimum required binder content and w/b ratio have been recommended. For both types of mixes, it has been observed that the average corrected compressive strength of paver blocks as well as ultimate breaking load of paver blocks increases as the binder content increases and w/b ratio decreases. Therefore, it is recommended to use higher binder content with lower w/b ratio for heavy traffic category applications. Parametric study is also carried out to evaluate effect of the change in mechanical properties by changing the shape of the paver blocks. Investigations are conducted on various shapes of paver blocks such as zig-zag to hexagon as well as brick. Also change in mechanical properties is evaluated by changing the thickness from 60 mm to 80 mm. For both 60mm and 80mm thick paver blocks, compressive strength of paver blocks has been observed at par for zig-zag and hexagon paver blocks. Ultimate breaking load of paver blocks increases as the thickness of the paver blocks increases from 60 mm to 80 mm for the same shape of paver blocks. However, the performance of hexagon paver blocks has been observed at par with zig-zag paver blocks. It is also recommended to use 80 mm thick paver blocks for very loading requirements. Present investigation on concrete paver blocks has given a idea to use different industrial byproducts for the production of concrete paver blocks. Use of aluminum AL6061-T6 can also be recommended for the production of concrete paver blocks. Although, practicality of using aluminum AL6061-T6 and other industrial by-products for pavement stretch applications is yet to be investigated.