Abstract
Lightweight aggregate for concrete was manufactured from recycling the waste PET bottles (PET Bottle Lightweight Aggregate, LAPET). The qualities of LAPET and its mortar were investigated. Specific gravity and unit weight of LAPET was very low in comparison with river sand like as 1.39, 844 kg/㎥ respectively. In addition, compressive strength of concrete significantly decreased because of specific gravity of aggregate decreased with increases in containing ratio. When LAPET was contained to 25% and 50％ of river sand, compressive strength of concrete at 28 days was indicated more 30MPa. Most of LAPET was generally showed to round shape and fluidity of mortar increased significantly due to sleeking the surface texture of LAPET. On the other hand, capillary absorption of mortar with LAPET was greatly increased in comparison with that of mortar without LAPET because of LAPET was composed of singular gradation. Absorption of LAPET was 0％ because the interior structure of LAPET consists of PET like as organic high polymer. Therefore the fault of normal lightweight aggregate, absorption, will be improved. It could expect several advantages that the pollution of environment will be previously prevent and the waste resources could be recycled if LAPET is reused as aggregate for Lightweight concrete.
폐 PET 병을 재가공하여 콘크리트용 경량골재(LAPET)로 제조하였으며, LAPET의 품질 및 LAPET사용 모르터의 물성에 대하여 검토하였다. LAPET의 비중 및 단위용적 중량이 각각 1.39 및 844 kg/㎥로 강모래에 비하여 매우 작으며, LAPET의 혼합률이 클수록 골재의 비중이 작아지므로 강도가 크게 떨어졌으나, LAPET를 25 및 50%로 혼합한 경우 재령 28일 압축강도는 30 MPa 이상의 강도를 발현하였다. LAPET의 입형은 대부분이 일정한 형대로 둥근 모양을 지니고 있었으며, 표면조직이 매끄러워 모르터의 유동성을 크게 향상시켰다. 한편, LAPET가 단입도로 구성되어 있어 모르터의 모세관 흡수량은 LAPET를 혼합하지 않은 모르터에 비하여 크게 나타났다. LAPET의 내부구조는 유기질 계통의 고분자 재료인 PET로 구성되어 있어 흡수율이 0％이므로 일반 경량골재의 단점을 개선하는 효과가 있었으며, LAPET를 경량콘크리트용 골재로 재이용하게 되면 폐 자원 재활용 및 환경오염을 미연에 방지하는 일석이조의 효과가 기대된다.
