The adoption of constructional paper pipe die as the template of reinforced concrete columns can reduce multi-piece splicing when traditional wooden template is applied in columns, which may produce more interfaces and is easy to cause mold explosion or imperfect construction surface of casted concrete. The dimensions of paper pipe die have higher fineness. Furthermore, it only needs to change basic steel mold to produce paper pipe die with different dimensions in quantity. When it is applied in actual construction cases, it has larger usable dimension flexibility, and it can avoid causing multiple times of construction as the basic mold manufacturing cost is too high and construction is restricted by the quantity of molds.
With questionnaires and interviews, the study obtains the production mode and specification of constructional paper pipe die in Taiwan. Aiming to the construction case provided by paper manufacture which manufactures constructional paper pipe die in Taiwan, it takes case investigation and interview with construction and design units. With Internet telephone directory of Chunghwa Telecom Yellow Page, it collects 1175 paper manufactures, and it sorts out about 238 paper pipe manufactures from the business scope. After taking telephone interview preliminarily, 64 manufacturers are confirmed with paper pipe production. Then it takes questionnaire survey. Recollected questionnaires are 18 copies totally and manufacturers who receive interview are 13. Obtained paper pipe application cases are 18 totally.
In Taiwan, paper pipe has had more than 40 years of development history. Constructional paper pipe die production was started from ROC 67. Produced first batch of paper pipe die is applied on reinforced concrete columns of outdoor pavilions. Until ROC 85, it had dedicated constructional paper pipe die manufacturers. Constructional paper pipe die production is a complete production line, from raw paper splitting and racking, glue conveying, rolled into tube to cutting and delivery. The internal diameters of paper pipe die have certain restriction. Currently, max commonly customized length is 835CM and diameter is 20-105CM in Taiwan.
In Taiwan, constructional paper pipe die construction has common constriction process. After the paper pipe die is delivered to the construction plant, it takes four main steps, i.e. workability processing, positioning & assembly, grouting & form stripping and finished surface inspection. With case investigation, the results show among finished cases with application of constructional paper pipe die, it commonly has breakage, cut, dent and PE film damage. The cut has the highest proportion, which accounts 50% of the all cases. It is caused by cutting of electric saw for the convenience of removing when taking form stripping. The solution is to reduce the cutting depth of electric saw. When it is near the interior layer, it adopts art knife for cutting to avoid causing cut, or adopts paper pipe die with easy stripping technology.