Al-Qadisiyah Journal For Engineering Sciences, Vol. 9……No. 1 ….2016

EFFECT OF RC AND SBR AS COATING CURING MATERIALS

ON PROPERTIES OF HIGHWAY RIGID CONCRETE

PAVEMENT

Dr. Shakir Al-Busaltan
1
, Ma'aly Al-Ani

2
, Ola Al-Jawad

1 Lecturer, Department of Civil Engineering, University of Kerbala, Karbala, Iraq

shakerfa2003@yahoo.com

2 Asst. Lecturer, Department of Civil Engineering, University of Kerbala, Karbala, Iraq

masaasta@yahoo.com

3 Researcher, Department of Civil Engineering, University of Kerbala, Karbala, Iraq

aljawadola@yahoo.com

Received 21 September 2015 Accepted 9 December 2015

Abstract

The surface to volume ratio of concrete pavement is large, also, due to hot climate of Iraq, coating

concrete pavement after casting is essential to ensure vital curing, consequently to obtain

significant engineering properties. This research work reports the results of a study performed to

evaluate the engineering properties of concrete coated with concrete surface coatings solutions; two

types of coating were used representing co-polymer (Styrene-Butadiene Rubber, SBR) and by-

product material (Residue Crude, RC). Different coating solutions were prepared from these

solutions, individually and collectively; i.e. 100% SBR, 75% SBR+25% RC, 50% SBR+50% RC,

25%SBR+ 75%RC, and 100%RC. The engineering properties of the uncoated and coated concrete

samples were evaluated by assessing compressive strength, flexure strength and hardness for

concrete convenience for highway rigid pavement. The compressive strength was evaluated for the

specimens at 7, 14, 28 and 90 days, where flexure and hardness were evaluated at 28days.

The results showed that the coated samples with both SBR and RC performed noticeably better in

contrast with uncoated samples under air-dry conditions. Additionally, obvious differences in the

performance of the collective solutions were recognized. From the results, however, local by-

product materials have been proven as a significant coating materials suitable to enhance the

concrete used for pavement purposes.

Keywords: Compressive strength, Concrete pavement, Flexural strength, RC, SBR.

الجاسئة طية انضاج على خواص خرسانة بلطات الطرقغكمواد ت SBRو RCتاثير

مهندسة عال الجواد م.م. معالي العاني شاكر البو سلطانم.د.

قسم الهندسة المدنية / كلية الهندسة قسم هندسة النفط و البتروكمياويات/ كلية الهندسة قسم الهندسة المدنية / كلية الهندسة

جامعة كربالء جامعة كربالء جامعة كربالء

mailto:shakerfa2003@yahoo.com
mailto:masaasta@yahoo.com
mailto:aljawadola@yahoo.com

Al-Qadisiyah Journal For Engineering Sciences, Vol. 9……No. 1 ….2016

الخالصة

من المالحظ ان نسبة السطح الى الحجم في الخرسانة المستخدمة للطرق عالية, كذلك بسبب الجو الحار في العراق, يكون تغطية

. يقر هذا البحث نتائج دراسة لحصول على خواص هندسية عاليةاالخرسانة بعد عملية الصب مهمة لضمان انضاج فعال, و بالتالي

) مادة بولمراتية(, ومادة ناتج SBRا بمحاليل. وهذا المحاليل هي مادة الستارين بيوتدين ستارين تقيم خرسانة مغطاة سطحي

من هذين المحلولين بشكل مفرد او بخليط . عدة محاليل تغطية تم تحضيرها RCعرضي من الصناعة النفطية هي رواسب الخام

. تم تقيم SBR, 75% SBR+25% RC, 50% SBR+50% RC, 25%SBR+ 75%RC, 100%RC %100منهما:

الخواص الهندسية لنماذج الخرسانة المغطاة و غير المغطاة بمقاومة االنضغاط, مقاومة الكسر و الصالبة وبالطبع وفق متطلبات

يوم, بينما نماذج مقاومة 09, 82, 7,,4باعمار لمقاومة االنضغاط لنماذج اتقيم ستخدمة للبالطات الجاسئة . وتم الخرسانة الم

يوم. 82الكسر و الصالبة باعمار

بالمقارنة مع الخرسانة المتروكة بدون تغطية تحت تأثير SBRو RCطاة بال غوبينت النتائج زيادة ملحوظة في اداء الخرسانة الم

ان هناك فروقات ملحوظة ايضا في نتائج االداء حسب نوع المحلول المستخدم. وكنتيجة ملموسة تم اثبات فعالية الجو. كماحرارة

مادة ناتجة عرضيا من الصناعة المحلية في تحسين اداء الخرسانة المستخدمة في البالطات الجاسئة كمادة تغطية لالنضاج.

Abbreviations

ASTM American Society for testing and Materials

AASHTO American Association of State Highway and Transportation Officials

BS British Institute

CDC Coated before Dry Curing

DC Dry Curing

RC Residue Crude

SBR Styrene-Butadiene Rubber

SRA Shrinkage Reducing Admixture

WC Wet Curing

1. Introduction

The surface to volume ratio of concrete pavement is large. However, in hot weather climate

countries (such as Iraq), the need for providing supplementary protection to concrete pavement

where the pavement panels are in early curing age is well appreciated, as the final engineering

characteristics essentially related to. Excessive early-age evaporation will lead to insufficient water

that required for completing the hydration process. Moreover, this could result in plastic shrinkage

and cracking of the pavement surface, consequently low strength and durability, corrosion of steel,

and loss of pavement service life (Ye et al., 2010, American Concrete Institute, 2001). Actually,

one part water to 24 parts cement by weight is required during the earlier 7 days instead of the

depleted mixed water due to hydration process(American Concrete Institute, 1997).

Two methods are used broadly as curing methods in highway pavement constructions; namely,

supplying additional moisture by continuous application of water, or minimizing the water loss by

either sealing or covering the concrete surface. However, excessive research works have been done

to demonstrate the advantages and disadvantages of each curing method. Curing the pavement

panels by continuous application of water (which is commonly used in local pavement

construction) proved unsatisfactory, as the retention of water could be partially, furthermore, this

curing method result in a low wear-resistance of the pavement surface(Scripture, 1942). On the

other hand, burlap or insulating blankets respected as ideal curing method for retaining heat and

moisture, but intensive labor and time is required(Wang et al., 2006).

Al-Qadisiyah Journal For Engineering Sciences, Vol. 9……No. 1 ….2016

Significant number of studies have been conducted on the effectiveness of sealing materials. For

example, Wang et al. were found that the curing effectiveness is highly depends on the time of

application and the generic type of the curing membrane (Wang et al., 1994). Other study

conducted by Ibrahim et al. proved that the bitumen-based showed best performance as a curing

compound in contrast to coal tar epoxy, acrylic-based or water-based materials(Ibrahim et al.,

2013). In addition, they stated that initial period of water curing before curing compound is applied,

could be beneficial in improvement of concrete durability. Whiting and Snyder investigated the

effectiveness of high volatile organic compounds, low volatile organic compounds, plastic sheet

and convectional lab water curing, on concrete strength and permeability(Whiting and Snyder,

2003). The results of mentioned study demonstrated, firstly, that all curing method is significantly

better than no curing method in improving the strength and reduce the permeability of concrete.

Secondly, great difference between different curing compounds is also found, in other words, it is

not just sealing. The results of other attempt by Dang at el. Indicated that a double-coating by

Shrinkage Reducing Admixture (SRA) can clearly minimize the drying shrinkage and moisture loss

of concrete(Dang et al., 2013). Furthermore, water absorption rate and chloride penetration of the

tested concrete are reduced noticeably. The same results were proved by other research studies as

well (Saliba et al., 2011, Folliard and Berke, 1997, Bentz, 2006).

2. Research Aim and Scope

The present research work is aimed to investigate the effectiveness of a two curing compound

materials on mechanical properties of concrete use for highway pavement. The first compound is a

by-product material, which was selected as environmental friendly and cost effectiveness

alternative for the available curing compounds, i.e. Residue Crude (RC). While, another acrylic-

based compound widely utilized in concrete construction was selected for the following reasons:

 to minimize the RC dark color; it is believed that there is an essential relation between
darkness of exposed surface and the sunlight absorption by the concrete surface,

consequently, the rate of evaporation and the fresh concrete temperature.

 To minimize the RC viscosity; as shown in Figure 1 that incorporating SBR within RC,
reduce the viscosity significantly, and consequently facilitate the application of such

coating material in normal ambient temperature.

3. Research methodology
3.1 Materials and specimens preparation

The concrete mix used for the experimental program was compatible to the concrete specified by

the Iraqi requirements for concrete of highway pavement(State Orgnization of Roads and Bridges,

2003). Table (1) shows the mix constituents that used to prepare the cubs and prism specimens. At

least, three concrete cubes, or three prisms were prepared for each property variation. All the

specimens constituents were satisfied the said requirements regarding gradation, SO3 content,

soundness, material passing 200, etc.

Styrene-butadiene rubber (SBR) was utilized in the form of emulsion. Table (2) shows the physical

properties of the SBR. Where Table (3) shows the properties of RC which was received from Al-

Dura refinery plant as a by-product from distillation of crude oil.

3.2 Curing protocols
Three curing protocols were adopted in this study, consequently, three groups of specimens

prepared to test after the specified curing periods, i.e. 3,7 ,28, and 90 days. All the specimens in the

Al-Qadisiyah Journal For Engineering Sciences, Vol. 9……No. 1 ….2016

three groups left, initially, in the mold for 24 hours before de-molding and subjected to the

classified curing protocol. However, first group specimens (wet curing, WC) immersed in water

curing tank, while, second group specimens (dry curing, DC) left outside the lab directly under

ambient weather conditions. The third group specimens (coated before dry curing, CDC), where the

specimens coated with curing solutions before subjected to cure outside the lab under the ambient

weather condition.

Five coating solutions were prepared from RC and SBR, individually and collectively; i.e. 100%

SBR, 75% SBR+25% RC, 50% SBR+50% RC, 25%SBR+ 75%RC, and 100%RC. These curing

solutions applied, firstly, to the upper face of specimen after 30 min of concrete casting, as can be

seen in Figure (2), and then the other faces were coated after the de-molding 24 hours period to

concrete casting. Table (4) illustrates the details of curing protocols and coating solutions.

3.3 Test methods
Concrete characteristics are frequently determined in mechanical and durability terms.

Compressive strength and modulus of elasticity, and less repeatedly, tensile strength, shrinkage and

creep are used as mechanical properties. Where, carbonation and chloride penetration resistance,

and less repeatedly, water absorption and air/oxygen permeability are used to define durability. On

the other hand, abrasion resistance is very rarely studied, comparatively; as the property is

important in a special concrete part such as dams, spillways, pavement and floor where erosion

action is expected (de Brito, 2009). In this research work, the influence of covering solution on the

properties of hard concrete was determined by the following procedures:

i. Moisture loss: cylindrical specimens 50 mm diameter x 20 mm height were prepared to
determine the moisture loss, according to ASTM C156 (ASTM, 2005), after 3, 6, 24, 48, 96,

192 and 336 hours of curing and/or application of covering solutions.

ii. Compressive strength: cubic specimens 100x100x100 mm were prepared to determine the
compressive strength, according to BS 1881-116 (British Standards Institution, 1983), after

3, 7, 28, and 90 days of accomplishment of curing and/or application of covering solutions.

iii. Flexural strength: prism specimens 40x40x200 mm were prepared to determine the
flexural strength, according to AASHTO T-97 (AASHTO, 2003), after 28 days of

accomplishment of curing and/or application of covering solutions.

iv. Hardness of surface: cubic specimens 150x150x150 mm were prepared to determine the
hardness of the concrete surface using rebound hammer, according to ASTM C 805

(ASTM, 2002), after 28 days of accomplishment of curing and/or application of covering

solutions.

4. Results and Discussion
Moisture loss

Figure 3 demonstrates the moisture loss of cement mortar specimens coated with different
coating solutions. Results obviously showed that the most moisture lost occur in the early curing

time for all coated specimen types. However, it could be due to a combination of initial hydration

process, bleeding and evaporation. Furthermore, uncoated specimens (DC specimens) exposed

relatively higher loss of water. It is believed that unsealed surfaces demonstrates increment in the

probabilities of evaporation from the surface, then, the dried upper portion minimizes the

capillaries water from lower portion of the specimen by suction. In contrast, coated specimens

(CDC specimens) disclosed significant saving of capillaries water, but with noticeable variation

depends on the type of coating solution. However, it is suggested that the ability of the RC to

prevent evaporation is more substantial than SBR. It is may be due to natural of the material itself,

but also it could be due to the final ability of the material to supply sound thin cover. Results of

optical microscopy picture suggested that the SBR thin layer showed some fragments, in contrast to

Al-Qadisiyah Journal For Engineering Sciences, Vol. 9……No. 1 ….2016

RC, which showed a complete homogenous tight layer, as can be seen in Figure 4. Thus, the hair

space between these fragments could be represent evaporation zones.

Of course the results of loss of moisture reflect the variation in abilities of different solution

to save retention water required to continue the hydration process and produce more

hydration products, consequently, enhance the mechanical properties of the produced

concrete which will be proven hereafter. Furthermore, minimizing the loss of moisture

reduces the plastic shrinkage and tensile stress which could occur in the surface of the

concrete and specially in pavement panels due to volume to surface are ratio (Neville and

Brooks, 2010).

4.1 Compressive strength
As expected the development in compressive strength of specimens under continuing wet curing

showed significant value in contrast to air dry curing without coating, this has been confirmed for

all curing ages, as can be seen in Figure 5. In other words, the ratio of compressive strength over

curing age of WC/ DC ranged from 118- 164 %, Figure 6, which alarms a noticeable reduction in

strength in hot and dry weather climate, due to loss of water that necessary for continuation of

hydration process. This range reflects the importance of the mention water; the low ratio noted in

early ages, then steadily increased between 7 and 28 days, as the free water in the capillaries bleeds

and evaporates, after that, slight difference between 28 and 90 days strengths’ values.

On the other hand, coating concrete with the mentioned curing solutions offered valuable increase

in compressive strength in contrast with uncoated specimens; again, this is confirmed for all curing

ages. For all coating solution types, the ratio of strength over curing ages of CDC/DW showed the

same trend regarding the development of strength. Although RC generally offer a better

preservation to hold water in contrast to SBR, but CDC2 specimens’ strength disclosed the higher

values, Figure 6. However, this proves that the mixture of RC and SBR with high RC value is

significant in preserve water in the capillaries of specimens subjected directly under sunlight, which

approves the validity of lowering the darkness of the coating solution. it may said that the

evaporation of water under direct sunlight is higher either with coating with RC, as the strength

result not follow the loss of water test, whereas the loss of water conducted in lab environment.

4.2 Flexural strength

Results of the flexural strength of coated and uncoated concrete prisms at the age of 28 days

(average of three results), are illustrated in Figure 7. The prisms had been subjected to the same

curing protocols that mentioned in Table 4. Mostly, the flexural strength disclosed the same trend

as the compressive strength testing behavior. Whereas, wet curing specimen showed the highest

flexural strength, where the dry curing specimens showed the lowest; the flexural strength ratio of

WC/DC was approximately 160%, as can be seen in Figure 8, normally because of the loss of

water that required for hydration process. Figures 7 and 8 obviously exposed that the high

percentage of RC solution added better enhancement to flexural strength of dry curing specimens in

contrast to SBR. The improvement in flexural strength ratio (CDC/DC) ranged from 9% with SBR

coating solution, and was increased with increase of the percentage of RC up to 75%, where the

improvement reached to about 30%. Then a reduction associated with specimens entirely coated

with RC. The same explanation adopted to compressive strength improvement that mentioned

previously might be adopted here as well, whereas the variation in ability of different type of

coating solution in preserve the required water could be after the continuity of the hydration

process, consequently development in flexural strength.

Al-Qadisiyah Journal For Engineering Sciences, Vol. 9……No. 1 ….2016

4.3 Hardness of surface
Resistance to wear or hardness is a vital characteristic for the concrete used for road purposes.

Obviously, course aggregates hardness resists most of the abrasion resistance of tires repetitions,

but the mortar hardness, simultaneously, represents the complementary skeleton of wear resistance.

Although within the last 50 years, a numerous researcher tried to find a good relationship between

compressive strength and rebound surface hardness, there is a significant diversity still found by

proposed models (Szilágyi et al., 2011). However, abrasion has to measure by a tool other than

compressive strength to represent the characteristics of concrete surface. The test method of

rebound number described in ASTM C805 (ASTM, 2002) could bring an effective tool to measure

the hardness of the concrete that facing vehicle tires, in other words abrasion resistance (Dhir et al.,

1991). Taking in to account the fact that the evaporation and bleeding occurs in the top surface of

the concrete panels, normally top lay of concrete panels represents the critical part, which should

check.

Rebound number was determined on three 150x150x150 mm cube concrete samples according to

ASTM C805 principles(ASTM, 2002), for each coating solutions and dry and wet curing protocol

specimens. The results of the rebound number test on concretes are graphically shown in Figure 9.

It was found that while the maximum rebound number was in WC specimens, the smallest was in

DC specimens, which is normal, as the evaporation and bleeding occur at the surface of concrete.

This process left the upper layer more permeable and has the lowest retention water that required

for hydration process, consequently weaker concrete that reflects less rebound numbers. With

respect to DC rebound numbers, CDC1, CDC2, CDC3,CDC4,and CDC5 showed 16%,20%,16%,

12% and 8%, enhancements, respectively, as a result of coating process, as can be seen in Figure

10 . The reason for these enhancements could be explained by the verity of different coating

solutions to preserve water. However, using these solutions present a development in abrasion

resistance in term of rebound number.

5. Conclusions

From results of this research work, the following can be concluded and recommended:

1. Incorporating SBR into RC significantly reduces the produced solution viscosity, which
bring a beneficial effect in terms of coating application process. However, the new

produced solution can be spread easily over the concrete pavement panels, without heating

process.

2. Application of coating solutions in hot weather climate, considerably reduce the loss of
water and evaporation of the water needed to continue the hydration process in the early age

of concrete.

3. Over all laboratory test results demonstrated significant improvements in mechanical
properties of the concrete that coated in contrast with uncoated air dried concrete, i.e., the

compressive strength, flexural strength and hardness increase with range between 8-64%

depends on solution type, property type and age of concrete.

4. Base on laboratory test results, application of a solution with 25% SBR and 75% RC on
concrete demonstrated the best practice for improving the mechanical properties of concrete

pavement. These results could be due to the effectiveness of the RC to provide sound layer

which prevent the water evaporation, at the same time, the incorporating of SBR help in

reduce the darkness of the surface where the absorption of the sunlight less, consequently

minimizing the surface layer temperature and the evaporation of the water.

5. Results proved that by-product bitumen base material such as RC could produce a
respectable and dependable coating compound, either if it use without any treatment or

modification, which bring outstanding beneficial impact on quality, environment and cost

of produced concrete.

Al-Qadisiyah Journal For Engineering Sciences, Vol. 9……No. 1 ….2016

Acknowledgment

The authors gratefully acknowledge the production division staff of Dura refinery plant for kind

help in supplysing the RC.

References

[1] AASHTO 2003. Standard Method of test for: Flextural Strength of Concrete (Using Simple

Beam with Third Point-Loading),AASHTO T-97. American Association of State Highway

and Transportation Officials,Washington,D.C.

[2] AMERICAN CONCRETE INSTITUTE 1997. GUIDE FOR CONCRETE HIGHWAY

BRIDGE DECK CONSTRUCTION. American Concrete Institute,USA.

[3] AMERICAN CONCRETE INSTITUTE 2001. Guide to Curing Concrete. American Concrete

Institute,USA.

[4] ASTM 2002. Standard Test Method for Rebound Number of Hardened Concrete. C 805,

American Aociety for Testing Material, West Conshohocken, PA 19428-2959, United

States.

[5] ASTM 2005. Standard Test Method for Water Retention by Liquid Membrane-Forming Curing

Compounds for Concrete. C 156, American Aociety for Testing Material, West

Conshohocken, PA 19428-2959, United States.

[6] BENTZ, D. P. 2006. Influence of Shrinkage-Reducing Admixtures on Early-Age Properties of

Cement Pastes. Journal of Advanced Concrete Technology, 4, 423-429.

[7] BRITISH STANDARDS INSTITUTION 1983. BS 1881-116: Testing concrete —Part 116:

Method for determination of compressive strength of concrete cubes. London, UK.

[8] DANG, Y., QIAN, J., QU, Y., ZHANG, L., WANG, Z., QIAO, D. & JIA, X. 2013. Curing

cement concrete by using shrinkage reducing admixture and curing compound.

Construction and Building Materials, 48, 992-997.

[9] DE BRITO, J. 2009. Abrasion resistance of concrete made with recycled aggregates.

International Journal of Sustainable Engineering, 3, 58-64.

[10] DHIR, R. K., HEWLETT, P. C. & CHAN, Y. N. 1991. Near-surface characteristics of

concrete: abrasion resistance. Materials and Structures, 24, 122-128.

[11] FOLLIARD, K. J. & BERKE, N. S. 1997. Properties of high-performance concrete containing

shrinkage-reducing admixture. Cement and Concrete Research, 27, 1357-1364.

[12] IBRAHIM, M., SHAMEEM, M., AL-MEHTHEL, M. & MASLEHUDDIN, M. 2013. Effect

of curing methods on strength and durability of concrete under hot weather conditions.

Cement and Concrete Composites, 41, 60-69.

[13] NEVILLE, A. M. & BROOKS, J. J. 2010. Concrete Technology, London, UK, Pearson

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[14] SALIBA, J., ROZIÈRE, E., GRONDIN, F. & LOUKILI, A. 2011. Influence of shrinkage-

reducing admixtures on plastic and long-term shrinkage. Cement and Concrete Composites,

33, 209-217.

[15] SCRIPTURE, E. W. 1942. Method of curing concrete.

[16] STATE ORGNIZATION OF ROADS AND BRIDGES 2003. GENERAL SPECIFICATION

FOR ROADS AND BRIDGES. Ministry of Housing and Construction, Iraq.

[17] SZILÁGYI, K., BOROSNYÓI, A. & ZSIGOVICS, I. 2011. Rebound surface hardness of

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Materials, 25, 2480-2487.

[18] WANG, J., DHIR, R. K. & LEVITT, M. 1994. Membrane curing of concrete: Moisture loss.

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Table (1): concrete mix constituents used to prepare concrete specimens

Constituent Cement content Coarse Agg. Fine Agg. W/c
Unite (kg/m

3
) (kg/m

3
) %

Value 375 1079 610 0.5

Table (2): Physical Properties of Styrene-butadiene rubber (SBR)

sp. gr.
(20 oC)

Viscosity

(20 C, cP)

(20 C)

Total solids

(wt%)

SBR 0.954 171 9.1 40

Table (3): Physical Properties of Residue Crude

sp. gr.
(20 C)

Viscosity

(20 C, cP)

Flash point

( C)

fire point

( C)

RC 1.001 2640 140 175

Al-Qadisiyah Journal For Engineering Sciences, Vol. 9……No. 1 ….2016

Table (4): details of curing protocols and coating solutions.

Protocol no. Abbreviation Before de-molding After de-molding

1 WC 24 hrs. in lab air curing temp. 25± 2 ºC, RH= 50±5 Continuous immersing in

water path at 20ºC ± 2 tile

testing time

2 DC 24 hrs. in lab air curing temp.= 25± 2 ºC, RH= 50±5 Continuous air curing out

side lab at temp.=34ºC ±

5 , RH=15±5,tile testing ti

3 CDC1 Specimens left to dry for 30 min, then coated the free surfa

ce with coating solution (100% Rc), after that left for 24 hr

s. in lab air curing temp.= 25± 2 ºC, RH= 50±5

Coating the other specime

n surfaces with coating so

lutions, then continuous ai

r curing outside lab at tem

p.=34ºC ± 5 , RH=15±5,ti

le testing time

CDC2 Specimens left to dry for 30 min, then coated the free surfa

ce with coating solution (75% RC+ 25% SBR), after that l

eft for 24 hrs. in lab air curing temp.= 25± 2 ºC, RH= 50±

CDC3 Specimens left to dry for 30 min, then coated the free surfa

ce with coating solution (50% RC+ 50% SBR), after that l

eft for 24 hrs. in lab air curing temp.= 25± 2 ºC, RH= 50±

CDC4 Specimens left to dry for 30 min, then coated the free surfa

ce with coating solution (25% RC+ 75% SBR), after that l

eft for 24 hrs. in lab air curing temp.= 25± 2 ºC, RH= 50±

CDC5 Specimens left to dry for 30 min, then coated the free surfa

ce with coating solution (100% SBR), after that left for 24

hrs. in lab air curing temp.= 25± 2 ºC, RH= 50±5

Figure (1): Coating solutions viscosity at 25 ºC

2260

106 85.4 52.6 25.4
0

250

500

750

1000

1250

1500

1750

2000

2250

2500

100 %RC 75% RC + 25% SBR 50%RC + 50% SBR 25%RC + 75% SBR 100%SBR

V
is

co
si

ty
(

C
P

)

coating solution type

Al-Qadisiyah Journal For Engineering Sciences, Vol. 9……No. 1 ….2016

Figure (2): Effect of coating solution type on moisture loss of cement mortar

0.5

1.5

2.5

3.5

0 50 100 150 200 250 300 350 400 450 500 550 600 650

M
o

is
tu

re
l

o
ss

,
(%

)

Time, (hrs.)

DC CDC1 CDC2 CDC3 CDC4 CDC5

a b

Figure(4): Optical Microscopy of a) RC, b) SBR

Figure (2): covering the specimens with curing solutions after 30min of casting

Al-Qadisiyah Journal For Engineering Sciences, Vol. 9……No. 1 ….2016

Figure (3): Effect of coating solution on compressive strength ratio

Figure (4): Effect of coating solution on flexural strength

1
1

7
.5

1
6

3
.9

1
5

7
.3

1
5

6
.3

1
0

2
.1

1
2

5
.6

1
2

1
.9

1
2

2
.6

1
0

7
.5

1
2

7
.6

1
2

5
.6

1
2

6
.7

1
1

0
.9

1
1

9
.3

1
1

7
.7

1
1

7
.1

1
0

8
.5

1
1

7
.3

1
1

1
.8

1
1

3
.1

1
0

6
.4

1
1

2
.4

1
0

9
.0

1
1

2
.3

100

110

120

130

140

150

160

170

3 7 28 90

C
o

p
m

re
ss

iv
e

s
tr

e
n

g
h

t
ra

ti
o

,(
%

)

Curing time, (days)

WD/DC CDC1/DC CDC2/DC CDC3/DC CDC4/DC CDC5/DC

4.66

2.91

3.62 3.78 3.46 3.33 3.19

WC DC CDC1 CDC2 CDC3 CDC4 CDC5

F
le

x
u

ra
l

st
re

n
g

h
t,

(
M

P
a

)

Coating solution types

1
7

3
2

3
8

.7
4
0

1
4

1
9

2
4

2
6

1
5

2
4

3
0

3
2

1
5

2
5

3
0

.9
3
3

1
6

2
3

2
8

3
0

1
6

2
3

2
7

2
9

1
5

2
2

2
6

.8
2
9

10.0

15.0

20.0

25.0

30.0

35.0

40.0

45.0

3 7 28 90

C
o

m
p

rs
iv

e
s

tr
e

n
g

h
t,

(
M

P
a

)

curing time, (days)

WC DC DCD1 CDC2 CDC3 CDC4 CDC5

Figure (5): Effect of coating solution on compressive strength

Al-Qadisiyah Journal For Engineering Sciences, Vol. 9……No. 1 ….2016

Figure (5): Effect of coating solution on Flexural strength ratio

Figure (6): Effect of coating solution on rebound number

Figure (7): Effect of coating solution on rebound number ratio

160.1

124.4
129.9

118.9
114.4

109.6

100.0

110.0

120.0

130.0

140.0

150.0

160.0

170.0

WD/CD CDC1/CD CDC2/CD CDC3/CD CDC4/CD CDC5/CD

F
le

x
tu

ra
l

S
re

n
g

th
R

a
ti

o
,

(%
)

Coating solution types

29
30

29
28

WC DC CDC1 CDC2 CDC3 CDC4 CDC5

R
e

b
o

u
n

d
n

u
m

b
e

Coating solution types

140.0

116.0
120.0

116.0
112.0

108.0

100.0

105.0

110.0

115.0

120.0

125.0

130.0

135.0

140.0

145.0

150.0

WD/CD CDC1/CD CDC2/CD CDC3/CD CDC4/CD CDC5/CD

R
e

b
o

u
n

d
n

u
m

b
e

r
ra

ti
o

,
(%

)

Coating solution types