Waste to wealth: The use of plastic waste to produce cheaper and better interlocking paving blocks

尼日利亚是非洲最大的垃圾产生国，每年产生约250万吨垃圾，其中拉各斯是36个州的罪魁祸首。最终进入垃圾填埋场的70%的塑料垃圾会被焚烧，以减少垃圾体积，以增加垃圾填埋场的容量。拉各斯1800万人口中有60%生活在贫民窟，每天生活费不足1美元。在堆填区，捡垃圾的人收集塑料（分类/清洗/包装）卖给回收商是常见的景象。拉各斯州支持采摘，因为它希望增加回收利用。然而，由于回收商很少，拾取者太多，供大于求，导致分类/洗涤/包装的废塑料价格低得离谱，每公斤约15奈拉（即3便士）。联锁铺路砖广泛用于社区道路、车道、停车场、机场等，尼日利亚的联锁铺路砖市场价值超过300万美元（market Publishers 2018）。它们是以水泥为基础的，由于成本高，大多数只有富人/社区或政府才能负担得起。生产还消耗高成本和含碳的自然资源（水泥中的石灰和沙子）。该项目旨在开发更经济实惠的连锁铺路砖，由回收“未洗涤”的塑料和少量沙子制成，并使用紫外线稳定剂防止降解。这将导致“未洗涤”塑料的价格上涨，并支持更好/更安全/更健康/更可评估的塑料聚合方式。

Nigeria is the largest waste generator in Africa, generating about 2.5million-tons/annum, with Lagos, the major culprit of the 36 states. 70% of plastic waste that ends up in landfill gets burnt to reduce volume for increased landfill capacity. 60% of Lagos' 18million population live in slums and below $1/day. Waste-pickers collecting plastics (sort/wash/pack) to sell to recyclers is a common sight in landfills. Lagos state supports the picking due to its desire to increase recycling. However, with few recyclers and too many pickers, supply is outpacing demand leading to ridiculously low prices of around 15naira/kg (i.e. 3-pence) of sorted/washed/packed waste plastics.Popularly used for community-roads, driveways, parking areas, airports, etc., interlocking paving blocks market in Nigeria is worth over 3-millions dollars (Market Publishers 2018). They are cement based and mostly only affordable to rich people/communities or governments due to high costs. Production also consumes natural resources with high cost and embodied carbon (lime through cement, and sand). This project seeks to develop more affordable interlocking paving blocks, produced from recycling 'unwashed' plastic and little sand with u.v. stabilisers to prevent degradation. This will lead to higher prices for 'unwashed' plastics and support better/safer/healthier/more-estimable means of plastics aggregation.