鉄筋コンクリート造外壁のひびわれ対策における収縮目地の効果に関する研究

概要

論文の詳細を見る
Cracks which is occuring in external reinforced concrete walls due to shrnkage, temperature stress, etc. result in functional deterioration evidenced by such problems as leakage, spoiling of appearance and loss of structural durability due to rusting of reinforcement. The effectiveness of using control joints as a predictable countermeasure of crack development was researched by investigating seven buildings having such control joints. From the investigation it became evident that if there are control joints in a wall at intervals of less than 3 meters with joint depths of at least 20 per cent of the wall thickness, over 70 per cent of the cracks develop in the control joint. Therefore, it becomes evident that such a crack, sealed and waterproofed, can be a good countermeasure for cracking in general. It was also determined that the effectiveness of a contorol joint to concentrate cracking deteriorates when the joint dose not satisfy the depth and interval requirements stated above or if there are decorative joints in the wall or if joints are lacking at sides of openings. A method for determining the effectiveness of control joints prior to construction was developed by calculating a concentration factor (per centage of cracks occurring in control joints) with a statistical method and using the survey data of seven buildings.
社団法人日本建築学会の論文
1988-10-30