The use of recycled concrete aggregates in Portland cement concrete and granular road base or sub-base works has increased steadily all over the world in order to conserve the limited natural aggregate deposits. The recycling of the demolished concrete aggregate for the use in concrete or granular pavement works will not only help to protect the environment but also an economical benefit to the user. The main drawback for the bulk utilization of demolished or recycled aggregate is its characterization and proper quality control during its production. The overall objective of this research was to characterize recycled concrete aggregates (RCA) obtained from a demolished foundation structure and to determine its suitability for Portland Cement Concrete (PCC) works and use as a granular road base or sub-base material. Tests were carried out on RCA samples to determine whether it meets the specification for concrete aggregate material or a granular road base and sub-base materials. Several concrete mixes consisting of 10, 20, 30, 40, 60, and 80 % replacement of natural coarse aggregates (NCA) with RCA were prepared and tested for compressive strength after curing periods of 7, 14, and 28 days. The compressive strength of concrete made with various percentages of RCA decreased with increasing RCA content but it increased with curing period for all concrete mixes. The durability parameters of the natural aggregates and RCA samples were investigated by using sulfate soundness, rapid freeze-thaw and micro-deval tests to ascertain their chemical and abrasive resistance. The California Bearing Ratio (CBR) of RCA base was also compared with that of a natural road base material to determine its suitability for road base or sub-base works. In this study, the flakiness and elongation indices of the RCA were found to be better than that of conventional natural aggregates. The RCA base material had lower maximum dry density, higher optimum moisture content, and low California Bearing Ratio (CBR) value compared to the natural crushed rock base (NCRB) material but was found to be a relatively good road base material.

重大公共工程是健全都市及區域發展的重點之一，攸關全市居民生活品質。近年來台北市有許多重大公共工程完成或正在進行中，其中關於拆遷戶之安置方式，往往因資訊的不對稱，導致彼此的認知不同，因而產生許多紛爭，造成拆遷戶與規劃工程單位之間的隔閡。鑑於公共工程之特殊性，拆遷戶很難於原地安置，特別是重大交通工程及公園的開發等，雖說可以採用公共設施多目標發展之構想，於原地進行拆遷戶之安置，但能夠安置之數量有限，而且，也不是每一種公共工程皆適用此種開發方式，特別是交通工程的開發，影響範圍多呈線型，與一般呈現面狀的公共工程影響範圍不盡相同，因此，需要因應不同的公共工程之需求進行安置模式之選擇。 目前相關單位對於公共工程拆遷戶之安置，多採用「列入國宅等候名單優先購買或承租國宅」之方式，此種趨向一元化的安置方式，不僅無法滿足不同類型拆遷戶之需要，且模糊了國宅政策原本以協助低收入家庭的目的，更對其他國宅等候戶形成不公。經由案例的分析得知，台北市重大工程拆遷戶安置的課題，在經濟財務方面有拆遷戶認定的標準缺乏、未考量較難計量的損失、政府龐大的拆遷補償支出，在社會面之課題有拆遷戶分類方式之缺失、未考量弱勢團體之特殊需求，在法令制度面則有安置相關法令的缺乏、缺乏有效的實行機制、違章建築的處理及政治方面的協商等問題。 研究內容主要就經濟財務、社會及法令制度之觀點進行，重大工程拆遷戶安置情形、課題與理念之探討，由拆遷戶之權屬、身份、家庭收入、家庭組成型態等特性，進行類型之區分，建立台北市重大公共工程拆遷戶之分類，以及安置模式基本理念，對於拆遷戶之權益擬定計算之標準，與財務估算方式的建立，依據本研究對台北市重大公共工程拆遷戶之分類，研擬合宜之安置模式並加以評估，依據前述之分析，擬定安置計畫之可能內容，提供相關單位處理重大公共工程拆遷戶安置計畫法制化之建議，藉以修正以往過於簡化之安置方式。