A comparative study of type N mortars

Publisher’s version / Version de l'éditeur:

Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la

première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n’arrivez pas à les repérer, communiquez avec nous à PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca.

Questions? Contact the NRC Publications Archive team at

PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. If you wish to email the authors directly, please see the first page of the publication for their contact information.

https://publications-cnrc.canada.ca/fra/droits

L’accès à ce site Web et l’utilisation de son contenu sont assujettis aux conditions présentées dans le site LISEZ CES CONDITIONS ATTENTIVEMENT AVANT D’UTILISER CE SITE WEB.

Internal Report (National Research Council of Canada. Division of Building

Research), 1968-04-01

READ THESE TERMS AND CONDITIONS CAREFULLY BEFORE USING THIS WEBSITE. https://nrc-publications.canada.ca/eng/copyright

NRC Publications Archive Record / Notice des Archives des publications du CNRC :

https://nrc-publications.canada.ca/eng/view/object/?id=aec79c2a-5a9f-47c2-80d3-39fcb17f0823 https://publications-cnrc.canada.ca/fra/voir/objet/?id=aec79c2a-5a9f-47c2-80d3-39fcb17f0823

NRC Publications Archive

Archives des publications du CNRC

For the publisher’s version, please access the DOI link below./ Pour consulter la version de l’éditeur, utilisez le lien DOI ci-dessous.

https://doi.org/10.4224/20377778

Access and use of this website and the material on it are subject to the Terms and Conditions set forth at

A comparative study of type N mortars

NATIONAL RESEARCH COUNCIL O F CANADA DIVISION O F BUILDING RESEARCH

A COMPARATIVE STUDY O F T Y P E N MORTARS by J.I. Davison

ANALYZED

I n t e r n a l R e p o r t No. 359 of t h e Division of Building R e s e a r c h OTTAWA A p r i l 1968

A COMPARATIVE STUDY O F TYPE N MORTARS

PREFACE

This r e p o r t d e s c r i b e s f u r t h e r work done a s p a r t of the continuing study of m a s o n r y in the Atlantic Region with r e g a r d t o m a t e r i a l s ,

p e r f o r m a n c e and p r a c t i c e . T h r e e kinds of m o r t a r s , including s o m e made with m o r t a r m i x have been compared a s t o pertinent p r o p e r t i e s . The author, a m e m b e r of the staff of the Atlantic Regional Station of the Division in Halifax, i s engaged full t i m e in r e s e a r c h on masonry.

May 1968

Ottawa

N. B. Hutcheon A s s i s t a n t D i r e c t o r

A COMPARATIVE STUDY O F T Y P E N MORTARS

by

J.

I.

Davison

The i n c r e a s e d u s e of m a s o n r y c e m e n t s and packaged m o r t a r m i x e s in r e c e n t y e a r s h a s been accompanied by f r e q u e n t inquiries concerning the r e l a t i v e m e r i t s of t h e s e p r o p r i e t a r y

products and traditional c e m e n t - l i m e m o r t a r s . In the f a l l of 1964, a study of the p r o p e r t i e s of the r e s p e c t i v e m o r t a r s containing cementitious m a t e r i a l s commonly used in the a r e a was initiated; i t was completed in August 1967, when f r e e z e - t h a w cycling t e s t s on surviving m o r t a r cubes w e r e t e r m i n a t e d a t 567 cycles.

The p r o g r a m was designed to provide a c o m p a r i s o n of t h r e e m o r t a r s

-

1 : 1 :

6

P o r t l a n d c e m e n t : hydrated l i m e : sand, 1 : 3 m a s o n r y c e m e n t : sand, and m a s o n r y m o r t a r m i x : sand. The t h r e e combinations w e r e c o n s i d e r e d to be Type N m o r t a r s by Composition, a s defined by the National Building Code of Canada.

MATERIALS

All cementitious m a t e r i a l s w e r e obtained locally. They included a m a s o n r y cement, and a 1 : 1 : 6 m a s o n r y m o r t a r m i x containing P o r t l a n d c e m e n t and hydrated lime.

I t i s g e n e r a l l y understood that m a s o n r y c e m e n t i s p r o - duced by intergrinding c e m e n t clinker and limestone, while the p r o p r i e t a r y m o r t a r - m i x i s a m i x t u r e of P o r t l a n d c e m e n t and hydrated lime. Thus, in the m a s o n r y c e m e n t the limestone, a n i n e r t m a t e r i a l , i s simply a f i l l e r , while the hydrated l i m e i n the m o r t a r m i x a c t s a s a p l a s t i c i z e r and ultimately a s a cementitious m a t e r i a l when i t carbonates. In addition to t h e s e b a s i c ingredients both products contain c e r t a i n additives; f o r example, the p r e s e n c e of an a i r -entraining agent i s confirmed by t h e i r high a i r content levels.

I t should b e noted that the composition of t h e s e p r o p r i e t a r y products m a y be changed f r o m t i m e to t i m e a t the m a n u f a c t u r e r 1 s discretion, without notice to the c o n s u m e r . Thus, the data a c q u i r e d

in this study r e f l e c t the p r o p e r t i e s of the products available on the l o c a l m a r k e t in 1964 and a r e not n e c e s s a r i l y r e p r e s e n t a t i v e of s i m i l a r products c u r r e n t l y available.

In addition to local P o r t l a n d c e m e n t and hydrated lime, a n Arner ican-manufactur ed P o r t l a n d c e m e n t and a n A m e r i c a n - manufactured Type S hydrated lime, both a c q u i r e d during a r e c e n t ASTM Round-Robin m o r t a r t e s t s e r i e s , w e r e used in s o m e 1 : 1 :

6

m o r t a r s a m p l e s .

Air

-

entrained Cement-lime M o r t a r s

The p r o g r a m a l s o included conventional 1 : 1 : 6 c e m e n t - l i m e m o r t a r s with a i r - e n t r a i n i n g a g e n t s added to m a k e t h e i r a i r contents c o m p a r a b l e with that of the m a s o n r y m o r t a r m i x m o r t a r s . The a i r

-

entraining agent used was n e u t r a l i z e d vinsol r e s i n .

The a g g r e g a t e used was blended Ottawa sand, consisting of equal p a r t s g r a d e d and s t a n d a r d 20-30 m e s h .

PROCEDURES

P r o c e d u r e s outlined in the CSA Specification f o r M a s o n r y Cement A8-1956 w e r e u s e d except a s noted in the following p a r a g r a p h s .

P r e p a r a t i o n of M o r t a r

M a t e r i a l s w e r e proportioned by volume but a c t u a l

quantities w e r e weighed, using the r e s p e c t i v e weights calculated a s d i r e c t e d in CSA Spec. A8- 1956. The following unit weights w e r e u s e d a s a b a s i s f o r calculations: M a s o n r y c e m e n t

-

70 l b / c u ft. M a s o n r y m o r t a r m i x - 50 l b / c u ft. Hydrated l i m e

-

40 l b / c u ft. P o r t l a n d c e m e n t - 94 I b / c u ft. Sand - 80 I b l c u ft.

The mixing p r o c e d u r e s outlined in the Specification w e r e followed with the exception that m o r t a r s w e r e mixed to a flow of 120

₂

2 p e r c e n t instead of 105 to 115 p e r cent.

P l a s t i c M o r t a r

Air content and water retention w e r e d e t e r m i n e d on s e p a r a t e batches of the p l a s t i c m o r t a r s , and twelve 2-inch cubes w e r e molded f r o m each m o r t a r .

Hardened M o r t a r

The twelve cubes of each m o r t a r w e r e divided into four groups of three. The f i r s t two groups w e r e u s e d f o r com- p r e s s i v e s t r e n g t h t e s t s a t 7 and 28 days; the t h i r d group was u s e d f o r absorption t e s t s , and the l a s t group f o r f r e e z e - t h a w cycling.

The l a s t two t e s t s w e r e done a f t e r a 28-day curing period.

A b s o r ~ t i o n T e s t s

After the curing period, cubes w e r e d r i e d f o r 72 h o u r s a t 175 OF, their d r y weights r e c o r d e d , and absorption (when cubes w e r e s e t in w a t e r to a depth of

$

inch f o r 1 h o u r ) determined.

Following this the 24-hour i m m e r s i o n absorption was a l s o d e t e r m i n e d .

F r e e z e - thaw Cycling

Despite well recognized objections to rating the durability of m o r t a r cubes on the b a s i s of t h e i r r e s i s t a n c e to l a b o r a t o r y f r e e z e - thaw cycling, t h e s e t e s t s w e r e included in the a b s e n c e of a n a c c e p t - a b l e alternative. The cycling t e s t was a modified v e r s i o n of the t e s t u s e d f o r b r i c k s (CSA A82.2-1954, Standard Methods of Sampling and

Testing B r i c k ) i n which the cubes w e r e f r o z e n in a i r in a s a t u r a t e d condition and thawed in water. After being r e m o v e d f r o m the water, the cubes w e r e wiped s u r f a c e d r y and s e t out f o r f r e e z i n g on wooden s t r i p s in a m e t a l container, to p r e v e n t them f r o m r e s t i n g in any w a t e r that m i g h t d r a i n f r o m them.

RESULTS

A ) 1 : 3 m a s o n r y m o r t a r m i x

M o r t a r p r e p a r e d with 1 : 3 m o r t a r m i x : sand p r o p o r t i o n s a t a flow of 120 p e r cent showed low water retention and c o m p r e s s i v e s t r e n g t h values. B e c a u s e of this, two other t e s t s w e r e conducted using m o r t a r s p r e p a r e d under different conditions. One had the s a m e

p r o p o r t i o n s of cementitious m a t e r i a l and sand, but the flow was i n c r e a s e d to 135 p e r cent; in the second, the proportions w e r e a l t e r e d t o follow t h e recommendations of the m a n u f a c t u r e r ;

1 p a r t m o r t a r m i x was combined with 2$ p a r t s aggregate.

R e s u l t s of t e s t s on t h e s e t h r e e m o r t a r s a r e compiled in Table I. As noted above, the c o m p r e s s i v e s t r e n g t h value of 702 p s i a t 28 d a y s f o r the 1 : 3 m o r t a r m i x : sand a t 120 p e r cent flow was low and would c l a s s i f y the m o r t a r Type 0 r a t h e r than

Type N under the r e q u i r e m e n t s of the National Building Code. The water retention a t 64.7 i s below the m i n i m u m r e q u i r e m e n t of 70

in the ASTM Specification f o r M o r t a r f o r Unit M a s o n r y (C270). However, i t i s noted that the 64.7 value was obtained using an initial flow of 120 p e r c e n t r a t h e r than the 100 t o 115 p e r c e n t value defined in the ASTM Specification. The m o r t a r stiffened r a p i d l y when mixing was completed, and t h i s f a c t o r combined with the low values f o r retention and c o m p r e s s i v e s t r e n g t h (which w e r e confirmed by r e s u l t s of t e s t s on a duplicate m i x ) r e s u l t e d in a decision t o t e s t the m o r t a r a t a higher flow, 135 p e r cent. While this did not m a t e r i a l l y change the w a t e r r e t e n t i o n value, the

i n c r e a s e d water content r e s u l t e d in a substantially lower c o m p r e s

-

s i v e s t r e n g t h value.

The other alternative, the 1 : 2$ m o r t a r m i x : sand combination a t 120 p e r cent flow, produced a n a c c e p t a b l e 7 1.7 retention value and a 1222 p s i c o m p r e s s i v e strength, the l a t t e r well above the m i n i m u m r e q u i r e m e n t f o r a Type N m o r t a r .

The seven-day c o m p r e s s i v e s t r e n g t h t e s t s w e r e conducted t o provide a n e a r l y indication of the t r e n d of t h e r e s u l t s . They w e r e quite consistent with 28-day values and t h e r e f o r e have not been

inciuded in this r e p o r t .

F r e e z e - t h a w cycling t e s t r e s u l t s a r e s u m m a r i z e d in Table 11. Cubes w e r e c o n s i d e r e d to have failed when ( a ) s e v e r e cracking o r s u r f a c e spalling o c c u r r e d , o r (b) weight l o s s e s r e a c h e d 5 p e r cent of the original d r y weight. T h r e e of the f o u r cubes which failed, A8, H6, and K9, did s o b e c a u s e of weight l o s s e s (k., they gradually eroded away until the 5 p e r c e n t f i g u r e was s u r p a s s e d ) while K12 failed with a s e v e r e s u r f a c e spalling.

F i g u r e s 1 and 2 show the extent of the d e t e r i o r a t i o n in the m o r t a r m i x cubes (A, H, J ) that s u r v i v e d the 567 cycles. Top s u r f a c e s of the cubes a r e shown in F i g u r e 1, w h e r e m i n o r rounding of c o r n e r s i s noted. M o r e extensive d e t e r i o r a t i o n p a t t e r n s a r e a p p a r e n t in F i g u r e 2, w h e r e c o n s i d e r a b l e rounding of c o r n e r edges h a s o c c u r r e d on the bottom s u r f a c e s of the s a m e cubes.

It should b e noted that two of the t h r e e 1 : 2$ m o r t a r m i x : sand cubes (K), which had c o m p r e s s i v e s t r e n g t h v a l u e s a l m o s t double those of the other m o r t a r - m i x cubes, failed a f t e r 270 and 336 cycles, while the remaining cube had the lowest weight l o s s among cubes surviving the 567 cycles.

SUMMARY

The 1 : 2$ m o r t a r m i x : sand m o r t a r had water retention and c o m p r e s s i v e s t r e n g t h values which m e e t the r e q u i r e m e n t s f o r a Type N m o r t a r . Values f o r 1 : 3 m o r t a r m i x : sand m o r t a r s a t two flows did not m e e t water retention r e q u i r e m e n t s of ASTM C270, and their lower c o m p r e s s i v e s t r e n g t h values would c l a s s i f y t h e m a s Type 0 r a t h e r than Type N.

Despite i t s higher c o m p r e s s i v e strength, the 1 : 2:

m o r t a r m i x : sand cubes had the highest r a t e of f a i l u r e in f r e e z e - thaw t e s t s , followed by the 120 p e r cent flow 1 : 3 m o r t a r mix: s a n d and the 135 p e r c e n t flow combination. While none of the l a s t two types of cubes failed a f t e r 567 cycles, they showed the g r e a t e s t a v e r a g e weight l o s s e s and t h e r e f o r e the p o o r e s t durability.

In view of the r e s u l t s for t h e m o r t a r m i x m o r t a r s , the original intention to c o m p a r e the v a r i o u s m o r t a r s on the b a s i s of a 1 : 3 cementitious m a t e r i a l : sand proportion was a l t e r e d , and the m o r t a r m i x m o r t a r i s included on a 1 : 2 $ proportion b a s i s .

B) Conventional 1 : 1 :

6

Cement- Lime, 1 : 1 :

₆

Masonry Mortar Mix and Masonry Cement M o r t a r s

Results of t e s t s on the three types of m o r t a r s a r e compiled in Table 111. It includes four 1 : 1 :

6

cement-lime m o r t a r s , one containing American cement and lime, one of

local cement and lime, and one each of the above containing an air-entraining agent. The l a t t e r i s intended to r a i s e the a i r contents of the conventional cement-lime m o r t a r s to a compar- able level with the masonry m o r t a r mix. This was done using the 1 : 3 masonry m o r t a r m i x : sand a t 120 per cent flow a s a basis. Thus, a i r content values in the table f o r the air-entrained

cement: l i m e m o r t a r s a r e some 3 p e r cent higher than the value for the 1 : 2: m o r t a r mix: sand m o r t a r . Data in the table indicates that a i r content in the masonry cement m o r t a r i s 57.5 p e r cent higher than in the masonry m o r t a r mix. It i s a l s o interesting to note that a i r content in normal cement l i m e m o r t a r s i s 6.5 and 7.

6

per cent, with the one containing the Type S hydrate being 1.1 per cent higher than the one containing the local hydrate. The reduction in water requirement of the cement-lime m o r t a r s with the addition of an air-entraining agent a t constant flow (120 per cent) should a l s o be noted.

Water retention values (WRV) f o r a l l m o r t a r s exceeded the value of 70 required a s a minimum in ASTM Spec. C270. The two cement-lime m o r t a r s with high a i r contents had the highest WRV value

-

the highest individual value being recorded by the

American cement-lime m o r t a r . The masonry cement and the normal cement-lime m o r t a r s had comparable values with the masonry m o r t a r m i x having the lowest value.

The masonry m o r t a r m i x and the masonry cement m o r t a r s had the lowest 1-hour absorption ( r a t e of absorption) and the masonry cement m o r t a r a l s o had the lowest 24-hour immersion absorption, followed by the masonry m o r t a r m i x and the traditional cement-lime m o r t a r s in that order. The addition of an air-entraining agent had no effect on the American cement-lime m o r t a r but i t did r e s u l t in a reduction in absorption values for the local cement-lime combination.

Highest c o m p r e s s i v e s t r e n g t h values o c c u r r e d with the traditional c e m e n t - l i m e m o r t a r s . In fact, values f o r the m a s o n r y c e m e n t and the m a s o n r y m o r t a r m i x w e r e only 34 and 48 p e r c e n t respectively, of the a v e r a g e value f o r the two n o r m a l c e m e n t - l i m e m o r t a r s , Values f o r a l l m o r t a r s w e r e well above the minimum r e q u i r e m e n t s for a Type N m o r t a r , and the c e m e n t - l i m e m o r t a r s qualified by c o m p r e s s i v e s t r e n g t h a s Type S m o r t a r s . The addition of the air-entraining agent reduced the a v e r a g e c o m p r e s s i v e s t r e n g t h of the c e m e n t - l i m e m o r t a r s t o 64 p e r cent of the value f o r the non- a i r - e n t r a i n e d m o r t a r s . I t is notable that this reduction, attributed to the effect of the i n c r e a s e d a i r content, o c c u r r e d despite a r a t h e r substantial reduction in the water r e q u i r e m e n t . However, the

reduced c o m p r e s s i v e s t r e n g t h values f o r t h e high a i r content c e m e n t - l i m e m o r t a r s w e r e s t i l l well above the values f o r the m o r t a r m i x and m a s o n r y c e m e n t m o r t a r s , and well above the m i n i m u m r e q u i r e - m e n t f o r a Type N m o r t a r .

R e s u l t s of f r e e z e - t h a w cycling t e s t s on cubes of t h e s e m o r t a r s a r e s u m m a r i z e d in Table IV.

R e s i s t a n c e of m o r t a r s to f r e e z e - t h a w cycling c a n be r a t e d a s follows: 1 ) Cement-lime with high a i r content, 2) m a s o n r y

cement, 3) m a s o n r y m o r t a r mix, 4 ) n o r m a l c e m e n t lime. The c e m e n t - l i m e m o r t a r s with no a i r - e n t r a i n i n g agents failed a f t e r a n a v e r a g e of 74 and 119 c y c l e s

-

t h e l a t t e r f i g u r e indicated slightly higher r e s i s t a n c e f o r the A m e r i c a n c e m e n t - l i m e m o r t a r . However, the i m p r o v e m e n t over the l o c a l c e m e n t - l i m e m o r t a r was not significant by c o m p a r i s o n with the r e s u l t s f o r the o t h e r cubes. Two of the m a s o n r y m o r t a r m i x cubes failed a t a n a v e r a g e 303 cycles, while the s u r -

viving cube was in good condition with a weight l o s s of only 1. 6 p e r cent. None of the m a s o n r y c e m e n t c u b e s had failed a f t e r 567 c y c l e s

-

their a v e r a g e weight l o s s (2.1 p e r c e n t ) was c o n s i d e r e d to b e

m o d e r a t e and v i s u a l observation indicated i t t o be caused by l o s s of s m a l l p i e c e s f r o m c o r n e r s and edges accompanied by a minar rounding of edges. The high a i r content c e m e n t - l i m e m o r t a r s s u r v i v e d f r e e z e - thaw cycling in excellent condition: weight l o s s e s w e r e negligible and v i s u a l observation failed to r e v e a l any r e a l deterioration.

Cubes surviving 567 cycles of freezing and thawing a r e shown in F i g u r e s 1 and 2. However, the 1 : 2 i masonry m o r t a r mix cube i s not included; instead the 1 : 3 m o r t a r mix:

sand cubes A, H, and J a r e shown. Figure 2 illustrates the

pattern of deterioration

-

the masonry m o r t a r mix cubes gradually eroded away starting a t the c o r n e r s and edges. F a i l u r e occurred in these cubes when weight l o s s e s reached five per cent. There was some rounding of edges on the masonry cement cubes but weight l o s s e s were p r i m a r i l y the r e s u l t of broken corners.

P i c t u r e s indicated no change in the high a i r content cement-lime m o r t a r cubes.

SUMMARY

T e s t s on t h r e e m o r t a r combinations have indicated:

1) Masonry m o r t a r mix m o r t a r had a lower water retention than cement-lime and masonry cement m o r t a r s ; the l a s t two had comparable values.

2) Masonry cement m o r t a r had lowest over-all absorption values.

3 ) Cement-lime m o r t a r had best compressive strength values.

4) With one exception, masonry cement and masonry m o r t a r mix m o r t a r s performed better than cement-lime m o r t a r during .

freeze-thaw cycling tests.

5 ) The addition of an air-entraining agent to the cement-lime m o r t a r s r a i s e d their a i r content level f r o m 7 . 0 to 18.6 per cent. The r e s u l t was improved water retentivity, lower absorption and compressive strength values, and superior r e s i s t a n c e to freeze-thaw cycling.

C) 1 : 1 : 6 Cement-Lime M o r t a r s

-

Different Combination of Materials

In the previous section two cement-lime m o r t a r s were used, one containing American cement and l i m e and the other local

were done on two m o r e m o r t a r combinations, one containing American cement and local l i m e and the other local cement with American lime. Only a i r contents and compressive strength t e s t s were conducted.

A summary of results, including values for the original two m o r t a r s i s given in Table V.

RESULTS

The highest compressive strength value was obtained with the American cement and local lime, while the American cement and lime produced the second highest value, indicating that the American cement was slightly stronger than the local cement. However, the spread between the low and high values for the four combinations was only of the o r d e r of 13 per cent of the high value.

Both m o r t a r combinations containing the American

Type S hydrated l i m e had slightly higher a i r contents (approximately 1 per cent) than m o r t a r s containing the local hydrate.

On the b a s i s of the minor differences in results, i t would appear reasonable to suggest that the two cements and the two limes a r e comparable in quality insofar a s their use in 1 : 1 :

6

_cement-

lime m o r t a r i s concerned. Water retention values in Table

I1

indicate a superiority of the American Type S hydrated l i m e over the locallime, but m o r t a r s containing the l a t t e r adequately m e e t Specification requirements. There i s certainly no evidence in the data in this study to justify the c u r r e n t proposal in ASTM Committee C12 to eliminate Type N hydrated l i m e (Canadian hydrated lime qualifies a s Type N) f r o m the Specification f o r Mortar for Unit Masonry (C270).

T A B L E I1

RESULTS O F F R E E Z E - T H A W CYCLING T E S T S ON MASONRY MORTAR MIX MORTAR CUBES

Wt. L o s s ( p e r c e n t a g e of o r i g i n a l ) A f t e r 567 C y c l e s 3 . 9 3 . 5 Avg. 3 . 3 2 . 4 3 . 4 2 . 8 3 . 6 Avg. 3 . 6 4 . 4 1 . 6 Avg. 1 . 6 F r e e z e -Thaw C y c l e s t o F a i l u r e 523

-

-

-

-

- -

490

- - -

-

- -

- - -

- - -

-

-

-

- -

- 336 270 M o r t a r P r o p o r t i o n s 1 : 3 m o r t a r m i x : s a n d 120

70

_flow 1 : 3 m o r t a r m i x : s a n d 135% flow 1 : 2$ m o r t a r m i x : s a n d 1207'0 flow Cube No. A8 A9 A12 H6 H9 H12 5 6 J 9

J

12 K6 K9 K12

T A B L E

IV

RESULTS O F F R E E Z E - T H A W CYCLING TESTS

a = A m e r i c a n c e m e n t a n d Type S h y d r a t e d l i m e . b = b a l c e m e n t and h y d r a t e d l i m e .

*

= A v e r a g e c y c l e s t o f a i l u r e , 119, T y p e of f a i l u r e , s u r f a c e spalling. t = _{A v e r a g e c y c l e s t o f a i l u r e , 74. T y p e of f a i l u r e , s u r f a c e s p a l l i n g .} T h e s e c u b e s l i t e r a l l y exploded. M o r t a r M i x 1 : 3 m o r t a r m i x s a n d 1 : 1 : 6 P C : L : S a ) 7.60/oA/C a ) 18.8%A/C b ) 6 . 5 % A / C b) 18.50/oA/C 1 : 3 M C : S F r e e z e - Thaw C y c l e s t o F a i l u r e

- - -

336 270 164* 139* 53*

- - -

- - -

--

- 8 0 t 7 1 t 7 1+

- - -

- - -

- - -

-

-

-

- - -

- - -

Cube No. K6 K9 K12 B 8 B9 B 12 C 8 C9 C12 D8 D9 D l 2 E 8 E9 E l 2 L6 L9 L 12 Weight L o s s ( P e r c e n t a g e of O r i g i n a l ) A f t e r 567 C y c l e s 1. 6 0 . 3 0.2 A v e r a g e , 0 . 2 0 0.0 0.0 0 . 0 1 . 4 2 . 5 A v e r a g e , 2 . 1 2 . 3

T A B L E V P R O P E R T I E S O F F O U R 1 : 1 : 6 C E M E N T - L I M E M O R T A R S USING 2 C E M E N T S AND 2 L I M E S M o r t a r C o m p o s i t i o n I U. S . C e m e n t t l i m e L o c a l C e m e n t

+

l i m e U.S. C e m e n t

+

l o c a l l i m e L o c a l C e m e n t

+

U. S. l i m e W a t e r R e q u i r e m e n t ( m l ) 2 60 2 6 8 265 263 2 8 - D a y C o m p r e s s i v e S t r e n g t h ( p s i ) 2615 2 5 0 1 2744 2 3 9 8 F l o w

(%I

1 2 6 . 5 1 1 9 . 2 1 1 9 . 3 120.0 A i r C o n t e n t

(%I

7 . 6 6 . 5 6. 6 7 . 3

F i g u r e 1 Top S u r f a c e s of M o r t a r Cubes Surviving 567 F r e e e e - T h a w Cycles

A and H

-

1 : 3 m a s o n r y m o r t a r m i x : sand 1207'0 flow

J

-

1 : 3 m a s o n r y m o r t a r m i x : sand 135% flow

C

-

₁ : ₁ : 6 U. S. c e m e n t : U. S. l i m e : sand

E

-

1 : 1 : 6 l o c a l c e m e n t : l o c a l l i m e L

-

1 : 3 m a s o n r y c e m e n t : sand

Minor rounding of edges f o r A, H, J, and L cubes

F i g u r e 2 Bottom S u r f a c e s

-

S a m e M o r t a r s a s in F i g u r e 1

Note: Rounded edges and c o r n e r s f o r A, H, and J cubes. Minor rounding of edges and broken c o r n e r s f o r

L

cubes.