UNIRAP SYSTEMH I G H - H E A D M A T E R I A L D E L I V E R Y F O R S H O T C R E G R I D B E A M C O N S T R U C T I O N  

P u m p  

S t e e l p i p e  

Y - b r a n c h  

R e s i n - c o a t e d h o s e  

N o z z l e  

C o m p r e s s o r  

P r e s s u r e C o n t r o l l e r  

 P

 r

 e

 s

 s

 u

 r

 i

 z

 e

 d

 a

 i

 r

 a

 d

 d

 e

 d

 a

 t

 Y

 -

 b

 r

 a

 n

 c

 h

Using newly developed mix propotion with special admixtures, grid beams with a designs strength

of 24MPa are constructed.

Delivery System

1 

2 

3 

4 

Since 1960,s shotcrete-based grid beam structures have been increasingly installed as one of the

major slope stabilization methods in Japan. As the number of projects increased, demands to install

beams of higher strength at higher places prompted improvement of conventional spray gun based

installation system. UNILAP system was developed by Raito Kogyo to respond to the demands by

combining pumping delivery with shotcrete operation.

I n c o n t r a s t t o t h e c o n v e n t i o n a l s h o t c r e t i n g w h i c h  

u s e s a i r t o d e l i v e r m a t e r i a l s f r o m t h e p l a n t ,  

U N I R A P u s e s a h i g h - h e a d p u m p t o d e l i v e r t o a  

s h o t c r e t e p o i n t . P r e s s u r i z e d a i r i s a d d e d a t t h e  

Y - b r a n c h n e a r t h e n o z z l e . T h e n t h e m a t e r i a l s  

a r e b l a s t e d i n t o t h e f o r m s a s i n n o r m a l s h o t c r e t e  

o p e r a t i o n . T h e a i r p r e s s u r e i s p r o p e r l y c o n t r o l l e d  

w i t h r e g a r d t o f l u i d d y n a m i c s t o p r e v e n t  

t u r b u l e n c e a n d d i s p e r s i o n o f t h e m a t e r i a l .  

H i g h s t r e n g t h m o r t a r / c o n c r e t e  

This system minimizes the rebound which causes material loss and product deficiency.

H i g h q u a l i t y m o r t a r / c o n c r e t e  

Using high-head pump and special materials, this system can deliver wet mix to 135m vertically or 

to 660m horizontally.

D e l i v e r m a t e r i a l s t o 1 3 5 m i n h e i g h t o r 6 6 0 m i n d i s t a n c e  

Special formwork units help to construct the product being firmly attached to the slope surface.

U n i q u e f o r m w o r k m a d e o f w i r e m e s h  

5 

The material preparation process, including scaling, mixing and pumping, is fully automated to

achieve high product quality.

A u t o m a t e d p l a n t f o r r e l i a b l e q u a l i t y c o n t r o l  

UNIRAP Method

 

2006.066006

R A I T O K O G Y O C O . , L T D .  

UNIRAPMaterial

Product Quality

R A I T O K O G Y O C O . , L T D .  

4 

- 

2 

- 

3 5 , K u d a n  

- 

K i t a , C h i y o d a  

- 

K u , T o k y o 1 0 2  

- 

8 2 3 6 J A P A N  

T E L .  

+ 

8 1 3 

- 

3 2 6 5  

- 

2 5 0 6 F A X .  

+ 

8 1 3 

- 

3 2 3 0  

- 

1 7 0 9  

E - m a i l o v e r s e a s @ r a i t o . c o . j p U R L h t t p : / / w w w . r a i t o . c o . j p  

F r e s h m o r t a r b e f o r e d e l i v e r y  

C e m e n t  

F i n e a n d c o a r s e a g g r e g a t e  

W a t e r  

R S A a g e n t  

A E w a t e r r e d u c i n g a g e n t  

O t h e r a d d i t i v e s  

P r e m i x  

S l u r r y  

P r o j e c t  

L o c a t i o n  

H e i g h t o f S l o p e  

G r a d i e n t o f S l o p e  

B e a m T y p e  

C h o s h i D a m C o n s t r u c t i o n P r o j e c t  

S h i m a n e P r e f . , J a p a n  

1 2 0 m  

1 : 0 . 6 ( 7 0 ¡ )  

U R 3 0 0  

S l i c e d s e c t i o n C o r e s a m p l e s  

 As shown in the photos, a sliced section and coresamples of placed mortar/concrete are fairlyhomogeneous and least intervened by defectiverebounds. The high strength property of producthas also been demonstrated from compressiontests and steel-concrete bond strength tests.

UNIRAP uses plastic mortar/concrete to facilitate pumping delivery. Compressed air is added at the Ybranch near the shotcrete nozzle. Several admixtures, including special RSA agent and high-range AEagent, are added to avoid material segregation during delivery and to increase rheopectic property toprevent sagging/sloughing after placement. Due to the combined effect of the admixtures, the freshmortar/concrete loses flowability immediately after shotcreted, to be of medium slump.