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Expansion joints in masonry walls of industrial buildings
Emel'yanov, A. A.; National Research Council of Canada. Division of
Building Research
PREFACE
C r a c k i n g o f b u i l d i n g s due t o t e m p e r a t u r e changes h a s been and c o n t i n u e s t o be a problem i n b u i l d i n g d e s i g n and c o n s t r u c t i o n , P r o p e r s p a c i n g f o r e x p a n s i o n and c o n t r a c t i o n o f j o i n t s h a s n o t y e t been f u l l y d e t e r m i n e d and much more c o n t i n u e d s t u d y i s n e e d e d . T h i s p a p e r was t r a n s l a t e d from t h e R u s s i a n a s a c o n t r i b u t i o n t o w a r d s t h i s n e e d . The D i v i s i o n o f B u i l d i n g R e s e a r c h w i s h e s t o r e c o r d i t s t h a n k s t o M r . H . R . Hayes o f t h e T r a n s l a t i o n s S e c t i o n o f t h e N a t i o n a l S c i e n c e L i b r a r y f o r p r e p a r i n g t h i s t r a n s l a t i o n and t o M r . W.G. Plewes o f t h i s D i v i s i o n who checked t h e t r a n s l a t i o n .
Ottawa R . F . Legget
N A T I O N A I , lilC::j<l\IlCII CO1R!C 11 OF CANADA
Tcchrjlca!. T t ~ n n o l : ; i . l o n 1757
T i t l e : Expansion j o i n t 8 I n masonry w a l l s of l n d u s t r l a l b u i l d i n g s ( 0 tem e r a t u r n y k h s h v a k h v kamennykh s t e n a k h promyshlennykh z d a n i i 7
Author: A . A . Emellyanov
R e f e r e n c e : Promyshlennoe S t r o l t e l '8 t v o ,
( 5 )
: 17-20,1965
EXPANSION JOINTS I N MASONRY WALLS OF INDUSTRIAL BUILDINGS
( A s u g g e s t i o n )
F u l i - s c a l e o b s e r v a t i o n s and measurements of t e m p e r a t u r e deformations o f s u p p o r t i n g and s e l f - s u p p o r t i n g s t o n e w a l l s of i n d u s t r i a l b u i l d i n g s made by l a b o r a t o r i e s engaged i n c o r r e l a t i n g t h e e x p e r i m e n t a l d e s i g n work of TsNIISK*, Gosstroi*+ have shown t h a t d e t e r m i n a t i o n of t h e d i s t a n c e between expansion j o i n t s w i t h o u t t a k i n g i n t o account t h e s t r u c t u r a l p e c u l i a r i t i e s of s t o n e w a l l s and t h e r i g i d i t y of the s t r u c t u r e s connected w i t h them r e s u l t s i n s e r i o u s damage t o t h e w a l l masonry, Thus, i n t h e w a l l s of a b u i l d i n g of s i l i c a b r i c k ( ~ i g . 1 ) made with grade 25 mortar*** and w i t h a s t r u c t u r a l r e i n f o r c e m e n t (mesh) l a i d i n t h e j o i n t s , t h e d i s t a n c e between expansion j o i n t s ( 5 5 m ) met s t a n d a r d s p e c i f i c a t i o n s . N e v e r t h e l e s s , In t h e f i r s t y e a r of o p e r a t i o n , c r a c k s running from t o p t o bottom of t h e masonry formed i n t h e o u t e r w a l l s i n p l a c e s where t h e framework joined on t o b l o c k s of a u x i l i a r y rooms ( a x e s 213 and
18/19). li-nvestigations showed t h a t t h e c r a c k s occurred a s a r e s u l t of concen- t r a t i o n s of temperature deformations a t t h e s e p o i n t s . During t h e c o u r s e o f time t h e s i z e of t h e s e c r a c k s and t h e damage t o t h e masonry i n c r e a s e d . The width of t h e c r a c k s reached
1.5
-
4 cm. The s i l i c a t e b r i c k ( i n t h e a r e a of t h e c r a c k s ) had crumbled. During p e r i o d s of r a i n and thaw, t h e r e wasa
continuous flow of w a t e r I n t o t h e b u i l d i n g through t h e c r a c k s . Attempts t o s e a l t h e c r a c k s with cement m o r t a r were i n e f f e c t i v e . Why d i d t h e c r a c k s a p p e a r I n t h e masonry and why d i d t h e i n s t a l l a t i o n o f an expansion j o i n t n o t a c h i e v e i t s purpose?
The columns of t h e framework t o which t h e l o n g i t u d i n a l b r a c e s were welded were f i r m l y anchored t o t h e masonry. A s a r e s u l t , t h e masonry, i n s t e a d of b e i n g u n r e i n f o r c e d , became r e i n f o r c e d and c a p a b l e of a b s o r b i n g h o r i z o n t a l t e n s i l e s t r e s s e s . T h i s l e a d t o t h e o c c u r r e n c e of c r a c k s a t t h e p o i n t s where t h e b r a c e s t e r m i n a t e d . The n a t u r e of t h e c r a c k formation was determined by t h e method o f t y i n g t h e r e i n f o r c e d c o n c r e t e f l o o r s l a b s t o t h e c r o s s - w a l l s . When m o n o l i t h i c s l a b s were embedded I n t o t h e w a l l ( a l o n g a x i s 98/19), a b r e a k
T r a n s l a t o r 1s Notes:
*
P o s s i b l y t h e C e n t r a l S c i e n t i f f c Research k s t i t u t e of C o n s t r u c t i o n Design.**
S t a t e Committee on C o n s t r u c t i o n of t h e Council of M i n i s t e r s of t h e U.S.S.R.***
S t r e n g t h 8 of m o r t a r r e f e r r e d t o i n t h e B o l D s h a y a Sovetskaya EntsikPopediyai n t h e masonry occurred a t t h e column, b u t when p r e f a b r i c a t e d f l o o r s l a b s were l a i d w i t h o u t b e i n g embedded i n t o t h e w a l l ( a l o n g a x i s 2/3), c r a c k s formed
beyond t h e c r o s s - w a l l a s a r e s u l t o f t h e detachment of t h e c r o s s - w a l l from t h e remainder of t h e b u i l d i n g . Following t h e f r a c t u r e o f t h e masonry, c r a c k s began t o develop r a p i d l y .
F i g u r e 2 i l l u s t r a t e s t h e v a r i a t i o n i n t h e width o f t h e c r a c k s ( a and b ) and t h e expansion p o i n t i n r e l a t i o n t o t h e average t e m p e r a t u r e o f t h e w a l l :
av d l y
tav
= 0 . 5 ( t s+
t i n ) ,W
a v
-
average d a i l y s u r r o u n d i n g t e m p e r a t u r e ; where tstin
-
average d a i l y i n t e r n a l room t e m p e r a t u r e .T h i s r e l a t i o n s h i p h a s a l i n e a r c h a r a c t e r , which i s confirmed by t h e r e s u l t s of o b s e r v a t i o n s .
We know t h a t t h e a n n u a l v a r i a t i o n o f a v e r a g e d a i l y t e m p e r a t u r e s
i s
n e a r l y s i n u s o i d a l w i t h an a n n u a l p e r i o d ; hence, t h e c r a c k s expand a c c o r d i n g t o t h e same p a t t e r n .I n t h e t a b l e t h e g r e a t e s t measured expansions of c r a c k s (double amplitude) and expansion j o i n t s a r e given.
Wall a l o n g a x i s B Wall a l o n g a x i s A
G r e a t e s t range of temp. v a r i a t i o n s
t;V d l y Cracks mm Expansion j o i n t Cracks mm Expansion j o i n t
deg. a b rnm c d rnm
A s we can s e e from t h e t a b l e , expansions of c r a c k s and j o i n t s were n o t uniform. Thus, t h e expansion o f c r a c k s a and c was 1 . 5
-
2 . 5 t i m e s g r e a t e r than t h a t of t h e expansion j o i n t s . The e x p l a n a t i o n f o r t h i s i s t o be found i n t h e d i f f e r e n t c o n d i t i o n s under which t h e c o r r e s p o n d i n g w a l l s e c t i o n s were l a i d .Expansion j o i n t s played an i n s i g n i f i c a n t p a r t i n t h e o v e r a l l
d e f o r m a t i o n s . T h e i r s m a l l degree o f m o b i l i t y i s e x p l a i n e d by t h e f a c t t h a t t h e y a r e covered by l o n g i t u d i n a l b r a c e s which s e r v e d t o check v a r i a t i o n i n t h e s i z e of t h e j o i n t s . Temperature d e f o r m a t i o n s of t h e w a l l s o c c u r r e d mainly a s a r e s u l t of c r a c k s , which may be thought o f a s n a t u r a l l y caused expans ion j o i n t s .
ldall damage was c a u s e d by t h e s w i n g i n g o f t h e s e c t i o n o f t h e w a l l s o u t of t h e i r p l a n e d u r i n g t e m p e r a t u r e d r o p s a c r o s s t h e w a l l t h i c k n e s s , a s w e l l a s by d e f o r m a t i o n s i n t h e i r p l a n e .
F i g u r e
3
i n c l u d e s d e f o r m a t i o n g r a p h s o f t h e movement o f t h e w a l lAV o u t o f i t s p l a n e i n r e l a t i o n t o t h e t e m p e r a t u r e d r o p a c r o s s i t s t h i c k - n e s s t2 =
tr
d l ~-
t i n . The movement AV amounted t o 2 mm f o r 28Oc d r o p t2. D u r i n g t h e c o l d p e r i o d o f t h e y e a r (when t h e a i r t e m p e r a t u r e o u t s i d e t h e b u i l d i n g was lower t h a n i t was i n s i d e ) movements o f t h e s e c t i o n were o u t w a r d s , and when t h e t e m p e r a t u r e r e l a t i o n s h i p was r e v e r s e d t h e y were i n w a r d s . In t h e l a t t e r c a s e t h e d e f o r m a t i o n s were c o n s i d e r a b l y s m a l l e r t h a n i n t h e f o r m e r . Thus, c r a c k s and e x p a n s i o n j o i n t s i n t h e w a l l s o f h e a t e d b u i l d i n g s move i n t h e h o r i z o n t a l p l a n e i n two directions a t once: i n t h e w a l l p l a n e and o u t o f i t .The c i t e d d a t a i n d i c a t e s t h a t t h e o c c u r r e n c e o f c r a c k s a t t h e p o i n t s where t h e l o n g i t u d i n a l b r a c e s o f t h e framework end i s r e l a t e d t o t e m p e r a t u r e .
The second most i m p o r t a n t f a c t o r which conduces t o t h e f o r m a t i o n o f c r a c k s a t t h e i n d i c a t e d p o i n t s i s t h e p r e s e n c e o f t h e more r i g i d ( t i e d t o t h e r e i n f o r c e d c o n c r e t e f l o o r s ) w a l l s e c t i o n s o f t h e a u x i l i a r y rooms. C r a c k s i n t h e masonry o c c u r r e d i n t h e p l a c e s where t h e y j o i n e d r i g i d w a l l s e c t i o n s ( t i e d t o t h e r e i n f o r c e d c o n c r e t e f l o o r s ) on one s i d e , and masonry r e i n f o r c e d by l o n g i t u d i n a l b r a c e s on t h e o t h e r . It i s e v i d e n t t h a t i n t h e c a s e u n d e r c o n s i d e r a t i o n t h e e x p a n s i o n j o i n t s s h o u l d n o t have been p l a c e d i n t h e middle o f t h e b u i l d i n g , b u t a t t h e p o i n t s where t h e c r a c k s i n t h e masonry o l , i g i n a t e d . From an a n a l y s i s o f t h e b e h a v i o u r o f t h e e x p a n s i o n j o i n t s I t f o l l o w s t h a t i t i s e x p e d i e n t t o make l o n g i t u d i n a l b r e a k s i n t h e framework a t t h e e x p a n s i o n j o i n t s by i n s t a l l i n g t w i n columns. A l l o f t h e f o r e g o i n g a p p l i e d t o w a l l s w i t h r e i n f o r c e m e n t s o f c o n s l d e r - a b l e l e n g t h ( r e i n f o r c e d s t o n e and r e i n f o r c e d c o n c r e t e b a n d s , m o n o l i t h i c f l o o r s embedded i n t h e w a l l s , m e t a l b r a c e s , r e i n f o r c e d c o n c r e t e o r m e t a l beams and s t r a i g h t a r c h e s o f c o n s i d e r a b l e l e n g t h ) , where t h e masonry i s c a p a b l e o f t a k i n g c o n s i d e r a b l e t e n s i l e s t r e s s e s . Where t h e r e a r e n o s u c h b r e a k s i n t h e framework, t h e q u e s t i o n o f e x p a n s i o n j o i n t s i n s t o n e w a l l s must b e r e s o l v e d on t h e b a s i s o f t h e f o l l o w i n g c o n s i d e r a t i o n s . Non- r e i n f o r c e d masonry, l i k e c o n c r e t e , d o e s n o t r e a c t w e l l t o t e n s i o n . The t e n s i l e s t r e n g t h T o f masonry o f r e g u l a r shaped s t o n e s v a r i e s between
1
-
3.5
kg/cm2 d e p e n d i n g on t h e q u a l i t y o f t h e m o r t a r , whereas t e m p e r a t u r e2
stresses may b e a s much a s
5
-
1 0 kg/cm,
o r e v e n g r e a t e r .o c c u r i n t h e masonry, which p a r t i a l l y r e l i e v e t e m p e r a t u r e s t r e s s e s . D i s p l a c e m e n t s a t t h e j o i n t s (sometimes w i t h o u t t h e f o r m a t i o n o f c r a c k s ) a r e c h a r a c t e r i s t i c o f masonry i n which weak m o r t a r h a s been used (M-10 and l o w e r ) . l i i t h s t r o n g m o r t a r , c r a c k s a l s o form i n s t o n e . A c h a r a c t e r i s t i c f e a t u r e o f t e m p e r a t u r e s t r e s s e s , a s d i s t i n c t from s t r e s s e s caused i n s t r u c t u r e s b y e x t e r n a l l o a d s , i s t h e f a c t t h a t t h e s e i n t e r n a l , e v e n l y d i a t r i b u t e d f o r c e s do n o t a l w a y s d i s a p p e a r c o m p l e t e l y on t h e f o r m a t i o n
o f c r a c k s . It i s p r e c i s e l y f o r t h i s r e a s o n t h a t c r a c k s a r e n o t c o n c e n t r a t e d i n one p l a c e i n hon~ogeneous n o n - r e i n f o r c e d masonry, b u t a r e d i s t r i b u t e d e v e n l y a l o n g t h e p l a n e o f t h e w a l l where t h e r e a r e t e n s i l e s t r e s s e s i n e x c e s s o f T.
F i g u r e 4 d e p i c t s a r e a s o f c r a c k f o r m a t i o n i n t h e w a l l s o f two b u i l d i n g s o f t h e same l e n g t h , i n one o f which t h e r e i s a n e x p a n s i o n j o i n t . The a r e a s o f c r a c k f o r m a t i o n a r e bounded b y l i n e s o f e q u a l t e n s i o n t e m p e r a t u r e
s t r e s s e s , c a l c u l a t e d i n a c c o r d a n c e w i t h t h e e l a s t i c i t y t h e o r y , and e q u a l t o t h e t e n s i l e s t r e n g t h T o f t h e w a l l m a t e r i a l . The i d e n t i c a l l i m i t s o f c r a c k development have been confirmed by a c t u a l o b s e r v a t i o n s .
Even when t h e l e n g t h of t h e b u i l d i n g was reduced by h a l f ( ~ i g . 4 b ) t h e a r e a o f c r a c k f o r m a t i o n ( a 2 T ) d i d n o t d i s a p p e a r , b u t changed i t s form. Thus, t h e i n s e r t i o n o f e x p a n s i o n j o i n t s a t i n t e r v a l s i n non-
r e i n f o r c e d wa1l.s d o e s n o t have t h e e f f e c t o f e l i m i n a t i n g c r a c k f o r m a t i o n . From a n e x a m i n a t i o n o f t h e n a t u r e o f t h e development o f t e n s i l e s t r e s s e s i n w a l l s I t a p p e a r s t h a t c r a c k s must be e v e n l y d i s t r i b u t e d , and c o n c e n t r a - t i o n s o f d e f o r m a t i o n s which l e a d t o t h e f o r m a t i o n of s i n g l e c r a c k s w i l l n o t o c c u r i n n o n - r e i n f o r c e d homogeneous w a l l s . In w a l l s w i t h window o p e n i n g s a t r e g u l a r i n t e r v a l s , v e r t i c a l c r a c k s a p p e a r a t t h e weakest p o i n t s n e a r t h e w i n d o w s i l l s ; c r a c k s seldom o c c u r i n t h e i n t e r f e n e s t r a t i o n s . A s a r e s u l t of t h e i r even d i s t r i b u t i o n i n t h e p l a n e o f t h e w a l l , t h e c r a c k s do n o t , a s a r u l e . , expand t o a n y g r e a t w i d t h and c o n s t i t u t e no t h r e a t t o t h e s a f e t y and d u r a b i l i t y o f t h e b u i l d i n g . T h i s
i s confirmed by a c t u a l measurements o f d e f o r n l a t i o n s due t o t e m p e r a t u r e and m o i s t u r e i n r e i n f o r c e d and n o n - r e i n f o r c e d b r i c k w a l l s .
Curves showing t h e h o r i z o n t a l t e m p e r a t u r e d e f o r m a t i o n o f non-
r e i n f o r c e d and r e i n f o r c e d b r i c k w a l l s ( a c t u a l . measurements) and t h e o r e t i c a l d e f o r m a t i o n s based on c a l c u l a t i o n s a r e g i v e n i n P i g .
5 .
D e f o r m a t i o n s i n t h e n o n - r e l n f o r c e d masonry o f lower s t o r e y s proved t o be3
-
5
times sma l l . e r t h a n t h o s e o c c u r r i n g i n r e l n f o r c e d masonryD e f o r m a t i o n s o f r e i n f o r c e d w a l l s K" were found t o be c l o s e t o e l a s t i c
K e ; d e f o r m a t i o n s of n o n - r e i n f o r c e d w a l l s comprised a n e l a s t i c K " ~ and a r i g i d p a r t Drig
.
I n t h i s c a s e where 6 1
-
e x p a n s i o n w i d t h o f t h e c r a c k s ; n-
number o f c r a c k s . Thus d e f o r m a t i o n s o f reinforced w a l l s and n o n - r e i n f o r c e d w a l l s ,-n , ( 4 ) i=l D f o r e a c h f l o o r i s found t o be c o n s t a n t . T h e r e f o r e , t h e g r e a t e r t h e r number o f c r a c k s n , t h e s m a l l e r t h e d e g r e e o f t h e i r e x p a n s i o n Gi. S i n c e t h e number o f c r a c k s o c c u r r i n g i n n o n - r e i n f o r c e d w a l l s i s l a r g e , t h e i r d e g r e e of e x p a n s i o n w i l l be l l . m i t e d ( a n d , t h e r e f o r e , n o t a d a n g e r f a c t o r ) . Thus, on a c c o u n t o f t h e f o r m a t i o n o f m i c r o c r o c r a c k s and d i s p l a c e - ments o f masonry a t t h e j o i n t s , t h e rna,iority o f t h e t e m p e r a t u r e d e f o r m a t l o n s a r e a b s o r b e d by them.ble may draw t h e c o n c l u s i o n t h a t f o r homogeneous w a l l s t h a t a r e n o t r e i n f o r c e d o r do n o t have a n y s e r i o u s v e r t i c a l . weakness (window o p e n i n g s , t o o t h i n g ) , t h e i n s e r t i o n o f e x p a n s i o n j o i n t s
i s
n o t o b l i g a t o r y . There a r e numerous i n s t a n c e s on r e c o r d o f l a r g e s t o n e w a l l s ( 2 0 0-
3 0 0 m ) b e i n g c o n s t r u c t e d w i t h o u t e x p a n s i o n j o i n t s and n o t m a n i f e s t i n g any t e m p e r a t u r e damage. The b e h a v i o u r o f r e i n f o r c e d w a l l s u n d e r t e m p e r a t u r e e f f e c t s i s q u i t e d i s t i n c t from t h a t o f n o n - r e i n f o r c e d w a l l s . The r e i n f o r c e m e n t t a k e s t h e n t e n s i l e s t r e s s e s and p r e v e n t s t h e f o r m a t i o n o f c r a c k s ( t e n d s t o z e r o ) . $= 1 I n c o n n e c t i o n w i t h t h e f a c t t h a t t h e b a l a n c e o f tempera u r e d e f o r m a t i o n s i n f o r m u l a e( 3 )
and (11) must be a p p r o x i m a t e l y t h e same, d e f o r m a t i o n s a r ec o n c e n t r a t e d a t t h e e n d s o f t h e r e i n f o r c e m e n t . T h i s i s d a n g e r o u s i n c a s e s where c o n c e n t r a t i o n s r e a c h 1 a r g e p r o p o r t i o n s .
F i g u r e
6
i l l u s t r a t e s t h r e e t y p i c a l i n s t a n c e s o f damage t o r e i n f o r c e d w a l l s r e s u l t i n g from c o n c e n t r a t j o n s o f d e f o r m a t i o n s a t t h e e n d s o f r e i n f o r c e - m e n t s . With c o n t i n u o u s reinforcement b a n d s , damage r e s u l t e d a t t h e c o r n e r s of t h e w a l l due t o l a r r , e d i s p l a c e m e n t o and w a r p i n g ( F i g . 6 a ) , With d i s - c o n t i n u o u s b a n d s , c r a c k s a p p e a r e d i n t h e p l a c e s where t h e bands t e r m i n a t e d ( F i g . 6 b ) . blith bands a l o n g p a r t o f t h e l e n g t h of t h e w a l l ( d e s c r i b e d a b o v e ) , damage i n t h e form o f c r a c k s o c c u r r e d a t t h e e n d s o f t h e r e i n f o r c e m e n tT h u s , t h e q u e s t i o n o f p u t t i n g e x p a n s i o n j o i n t s i n t h e w a l l s o f buil.dine;s depends on w h e t h e r o r n o t t h e y a r e t o have r e i n f o r c e m e n t s .
J u d g i n g by t h e examples we have examined, i t i s c l e a r t h a t , i n d e t e r r n i n i n ~ t h e d i s t a n c e s between e x p a n s i o n j o i n t s i n s t o n e w a l l 0 o f i n d u s t r i a l b u i l d l n g s , i t .Is n o t s u f f i c l . e n t siniply t o c o n s i d e r t h e g r a d e o f m o r t a r o r t h e e s t i m a t e d o u t s i d e a i r t e m p e r a t u r e . E x t e r i o r w a l l s , unbroken, o r p i e r c e d a t r e g u l a r i n t e r v a l s by window o p e n i n g o , when f r e e o f r e i n f o r c e m e n t s a l o n g t h e i r e n t i r e l e n g t h , may be c o n s t r u c t e d w i t h o u t J o i n t s , r e g a r d l e s s o f t h e g r a d e o f m o r t a r u s e d . I f t h e r e a r e w a l l r e i n f o r c e m e n t s ( n o t o n l y i n t h e form o f r e i n f o r c e d b r i c k o r c o n c r e t e b a n d s , b u t m o n o l i t h i c f l o o r s b u i l t i n t o t h e w a l l ) and l o n g , m e t a l o r r e i n f o r c e d c o n c r e t e beanls, s t r a i g h t a r c h e s , g i r d e r s , e t c
.
,
e x p a n s i o n j o i n t s s h o u l d be a t t h e p o i n t s where t h e y t e r m i n a t e , s i n c e i t i s p r e c i s e l y h e r e t h a t c o n c e n t r a t i o n s o f l a r g e t e m p e r a t u r e d e f o r m a t i o n s o c c u r , c a u s l n g t h e masonry t o f r a c t u r e and e v e n t u a l l y t o c o l l a p s e .F i g . 1 C r a c k s i n t h e b r i c k w a l l s of a n i n d u s t r i a l b u i l d i n g 1
-
i n t e r - s t o r e y f l o o r s of p r e f a b r i c a t e d r e i n - f o r c e d c o n c r e t e s l a b s n o t embedded i n t o w a l l a l o n g a x i s 2 1 3 ; 2-
i n t e r - s t o r e y f l o o r s of mono- l i t h i c r e i n f o r c e d c o n c r e t e embedded i n t o w a l l a l o n g a x i s 1 8 / 1 9 ; 3-
m e t a l s t r u t s ; 4-
l o n g i t u - d i n a l b r a c e s ; 5-
p r e - c a s t r e i n f o r c e d c o n c r e t e s t r a i g h t a r c h e s ; 6 - m e t a l a n c h o r s ; a , b , c , d-
p o i n t s a t w h i c h c r a c k s o c c u r r e d i n t h e m a s o n r yF i g . 2 Graphs s h o w l n ~ : v a r i a t i o n s i n t h e w i d t h oC c r n c k s n ( l ) , b ( 2 ) nnd j o i n t ( 3 ) i n relation t o ternperat-ure ( 4 ) F i g . 3 Graphs s l i o w i n g movement of c x p a n s i o n j o i . n t f r o m p l n n e o f wall V i n t i n re1:rt i on t o t c m p c r e t u r c ' d r o p a c r o s s wall t h i c k n e s s
F i g . 4
Areas of crack devrlopnient (shaded) i n s t o n e and concrete w a l l s of
d i f f e r e n t lengths
F i g . 5
Temperature deformation curves 1
-
non-reinforced w a l l s ;2
-
r e i n f o r c e d w a l l s ; 3-
t h e o r e t i c a lF i g . 6
Diagrams of darnage t o reinforced w a l l s 1
