ABSTRACT
A b s t r a c t Non-Exp los ive d e m o l i t i o n agen t (NEDA ) break s rock s an d concre t e q u i e t l y us in g expansiv e pressur e du r i n g h y d r a t i o n r e a c t i o n o f ca lc iu m ox ide w i t h o u t env i ronmenta l problems . Th e mechanis m o f expansiv e pressure gene ra t i o n i n NED A ha s no t bee n c l e a r l y proven , a l thoug h t h e r e ar e a numbe r o f t h e o r i e s t o e x p l a i n t h i s phenomenon . I t i s impor tan t t o c l a r i f y th e phenomeno n no t on l y t o mak e a n e f f e c t i v e d e m o l i t i o n p lan , bu t a l s o t o improv e NEDA . Th i s pape r examine s the r e l a t i o n s h i p amon g expansiv e energy , degre e o f r e s t r a i n t an d d i r e c t i o n o f r e s t r a i n t i n NEDA s unde r th e r e s t r a i n t o f i n s i d e an d o u t s i d e s t e e l p ipes . Expansiv e s t r a i n s o f a x i a l an d c i r c u m f e r e n t i a l d i r e c t i o n s wer e measure d b y w i r e s t r a i n gages . Th e conc lus ion s o f the exper iment s an d analyse s ar e a s f o l l o w s ; C a l c u l a t i n g equat ion s of expansiv e pressur e t r a n s f e r r e d t o th e eac h d i r e c t i o n o f NEDA s ar e proposed base d o n th e measure d expansiv e s t r a i n s a t th e su r fac e o f s t e e l p ipes . Radia l t r a n s f e r r e d expansiv e pressure s cause d b y i n s i d e s t e e l p ip e an d o u t s i d e s t e e l p ipe s ar e abou t th e sam e va lue . A x i a l t r a n s f e r r e d expansiv e pressure s unde r th e r e s t r a i n t o f ou t s i d e s t e e l p ipe ar e l a r g e r tha n thos e o f i n s i d e s t e e l p ipe . Radia l t r a n s f e r r e d expansive energ y become s l a r g e r a s th e r e s t r a i n t o f s t e e l p ip e becomes l a r g e r . Key Words : Non-Explos iv e d e m o l i t i o n agen t (NEDA) , Expansiv e energy , R e s t r a i n t o f i n s i d e an d o u t s i d e s t e e l p ipes , Degre e o f r e s t r a i n t , Rad ia l t r a n s f e r r e d expansiv e pressur e
1 I n t r o d u c t i o n
Non-Exp los ive d e m o l i t i o n agent s (NEDAs ) ar e w e l l accepte d w i t h i t s wide rang e o f a p p l i c a t i o n an d performances , becaus e d e m o l i t i o n wor k w i t h t h i s NED A f o r developmen t o f urba n an d i n d u s t r i a l area s i s saf e and f r e e f ro m no ise , v i b r a t i o n , an d f l y i n g deb r i s . Th e mechanis m o f expansive pressur e genera t i o n i n NED A ha s no t bee n c l e a r l y proven , a l t hough t h e r e ar e a numbe r o f t h e o r i e s t o e x p l a i n t h i s phenomenon . The f a s t a c t i n g grade s o f NED A hav e becom e a v a i l a b l e . I t i s impor tan t t o c l a r i f y th e phenomeno n no t on l y t o mak e a n e f f e c t i v e d e m o l i t i o n p lan , bu t a l s o t o improv e NEDA . C a l c u l a t i n g equat ion s o f expansive pressur e t r a n s f e r r e d t o th e eac h d i r e c t i o n o f NEDA s ar e
proposed base d o n th e measure d expansiv e s t r a i n s a t th e su r fac e o f s t e e l p ipes . Th i s pape r examine s th e r e l a t i o n s h i p amon g expansiv e energy, degre e o f r e s t r a i n t an d d i r e c t i o n o f r e s t r a i n t i n NEDA s unde r the r e s t r a i n t o f i n s i d e an d o u t s i d e s t e e l p ipes .
