Improvement of the strength of acrylic emulsion polymer modified mortar in high temperature and high humidity by blast furnace slag

KSCE Journal of Civil Engineering (2009) 13(1):23-30 DOI 10.1007/s12205-009-0023-x Structural Engineering www.springer.com/12205 Improvement of the Strength of Acrylic Emulsion Polymer-modified Mortar in High Temperature and High Humidity by Blast Furnace Slag Hyug-Moon Kwon*, Thuy Ninh Nguyen**, and Tuan Anh Le*** Received March 26, 2008 /Revised July 22, 2008/Accepted September 3, 2008 ··································································································································································································································· Abstract Polymer modification was widely used to improve the properties of construction materials The concept of polymer modification for mortar and concrete was put forward 80 years ago It was known that the use of polymers for modification can greatly improve the strength, adhesion, resilience, impermeability, chemical resistance and durability properties of mortars and concrete In southern Vietnam, a tropical weather country, the environment was usually hot with high humidity The durability of mortar or concrete coating was reduced over time in such a condition This study examines the strength of polymer-modified mortars in high temperature and high humidity Moreover, the results included the improvement of strength of acrylic emulsion polymer-modified mortar (PMM) by the addition of blast furnace slag Fifteen percent cement was replaced with blast furnace slag (BFS) in a mix proportion in order to improve strength of PMM The specimens were cured in cycles 50±2oC, RH 90±3%, for hours and 20±2oC, RH 60±3 %, for 19 hours per day The strength of PMM was measured at the age of 3, 7, 14, 21 and 28 days, and months and year in a high temperature and high humidity cycles Keywords: polymer-modified mortar, high temperature and high humidity cycles, blast furnace slag ··································································································································································································································· Introduction Cement mortar and concrete have some disadvantages such as delayed hardening, low tensile strength, high drying shrinkage, and low chemical resistance (Ohama, 1995) Polymer-modified mortar has been investigated In modern concrete construction and repair works the role of polymers was commonly used (Chandra, 1994) The properties of polymer-modified mortar depend on the type of polymer, the polymer-cement ratio, the water-cement ratio and the curing condition Previous researches on cement based mortar, polymer modified cement based mortars and epoxy mortars have shown that some of these materials did not perform well on hydraulic structures to satisfy site and climatic condition (Ru, 2002) Jenni et al (2006) had shown that there were reverse and irreversible changes in microstructures and physical properties of polymer-modified mortars during wet storage Hassan et al reported that the compressive strength of polymer modified concrete was slightly higher than normal concrete in a hot-dry environment (Hassan, 2001) In the tropical countries, there were two typical seasons: dry and rain In the summer time from May to September, especially in southern Vietnam, the temperature and humidity were usually very high (Information Center of Natural Resources and Environment, MORE) Polymer-modified mortars were used as the waterproof layer of structures and on the roof of buildings However, the quality of polymer-modified mortars was reduced after a short time Improving the strength of polymer-modified mortar in high temperature and high humidity was the main focus in this study Experiment 2.1 Materials An ordinary portland cement was used in this study The specific gravity was 3.15 g/cm3 and the Blaine’s specific area was 3,180 cm2/g The initial setting time was about 170 minutes and the finishing setting time was more than hours The particle size analysis of fine aggregate was described in Fig The specific gravity of fine aggregate was 2.65 g/cm3 Two kinds of acrylic emulsion polymer (AE) were used in this study were described in Fig and Table Blast furnace slag (BFS) was used in this study with 15% by weight of cement in mix proportion Properties of BFS were described in Table 2.2 Test program The mixing time was 150 seconds Specimens, 50×50×50 mm, were prepared for compressive tests (ASTM C 109/C 109M) *Member, Professor, Dept of Civil Engineering, Yeungnam University, Gyeongsan 712-749, Korea (E-mail: hmkwon@yu.ac.kr) **Lecturer, Dept of Civil Engineering, Ho Chi Minh City University of Technology, Vietnam (Corresponding Author, E-mail: nnthuy@hcmut.edu.vn) ***Doctoral Student, Dept of Civil Engineering, Yeungnam University, Gyeongsan 712-749, Korea (E-mail: tuanmaterial@yahoo.com) − 23 − Hyug-Moon Kwon, Thuy Ninh Nguyen, and Tuan Anh Le Fig Sieve Analysis of Sand Fig Temperature for the Cyclic Curing Conditions Table Mix Proportions b (%) Curing condition c BFS UM050d 0.50 : 100 20±2, RH 60% UM050h2 0.50 : 100 Cycle UM0050BFS 0.50 3:1 85 15 Cycle AE-0535d 0.35 : 100 20±2, RH 60% AE-0535h2 0.35 : 100 Cycle AE-0535BFS 0.35 3:1 85 15 Cycle AE-0540d 0.40 : 100 20±2, RH 60% AE-0540h2 0.40 : 100 Cycle AE-0540BFS 0.40 3:1 85 15 Cycle AE-1030d 0.30 10 : 100 20±2, RH 60% AE-1030h2 0.30 10 : 100 Cycle AE-1030BFS 0.30 10 3:1 85 15 Cycle AE-1035d 0.35 10 : 100 20±2, RH 60% AE-1035h2 0.35 10 : 100 Cycle AE-1035BFS 0.35 10 3:1 85 15 Cycle AE-1527d 0.27 15 : 100 20±2, RH 60% AE-1527h2 0.27 15 : 100 Cycle AE-1527BFS 0.27 15 3:1 85 15 Cycle AE-1530d 0.30 15 : 100 20±2, RH 60% AE-1530h2 0.30 15 : 100 Cycle AE-1530BFS 0.30 15 3:1 85 15 Cycle AE-1535d 0.35 15 : 100 20±2, RH 60% AE-1535h2 0.35 15 : 100 Cycle AE-1535BFS 0.35 15 3:1 85 15 Cycle AE-2025d 0.25 20 : 100 20±2, RH 60% AE-2025h2 0.25 20 : 100 Cycle AE-2025BFS 0.25 20 3:1 85 15 Cycle AE-2035d 0.35 20 : 100 20±2, RH 60% AE-2035h2 0.35 20 : 100 Cycle AE-2035BFS 0.35 20 3:1 85 15 Cycle AE-2040d 0.40 20 : 100 20±2, RH 60% AE-2040h2 0.40 20 : 100 Cycle AE-2040BFS 0.40 20 3:1 85 15 Cycle p: polymer; w: water, c: cement, s: sand; b: binder; BFS: blast furnace slag; UM: Unmodified mortar; d: curing 20±2oC, RH 60±3%; h2: cyclic curing conditions Code Fig Molecular Formula of Acrylic Emulsion Polymer Table Properties of Acrylic Emulsion Polymer AE1 Parameter AE2 Type Type Type Mw 1038744 122828608 1790754 390237 3.0 1.1 1.9 1.1 PDI Density (g/cm ) 1.04 1.04 Total solids (%) 53 52 Appearance Milky white Milky white Table Properties of Blast Furnace Slag Bulk density (kg/m3) 2.90 Fineness (cm /g) Activity index (%) SiO2 4,350 days 97 28 days 112 33.81 MgO (%) 5.55 SO3 (%) 2.21 LOI (%) 0.10 Specimens, 50 mm diameter and 100 mm height were prepared for splitting tensile tests (ASTM C496-96) Specimens, 40×40× 160 mm, were prepared for the flexural tests (ASTM C 348-97) After the specimens were casted, they were cured at 20±2oC and RH 60±3% for day After day, the specimens were cured in a cyclic condition: hours at 50±2oC and RH 90±%; 19 hours at 20±2oC and RH 60±3% The graph of temperature for the cyclic curing conditions was shown in Fig 2.3 Mix Proportion In this study, the sand-cement ratio was 3:1, the water-cement ratios were from 0.30 to 0.50 The polymer-cement ratios were: 5, 10, 15 and 20% (Table 3) − 24 − w/c p/c (%) s:b KSCE Journal of Civil Engineering Improvement of the Strength of Acrylic Emulsion Polymer-modified Mortar in High Temperature and High Humidity by Blast Furnace Slag Results and Discussions 3.1 Compressive Strength Compressive strength results of acrylic PMM were shown in Figs and and Table The early compressive strength of unmodified mortar for cyclic curing condition was higher than in normal condition However, the later compressive strength of unmodified mortar in cyclic curing condition was nearly the same in normal condition (Table 4) The highest compressive strength of PMM depended on polymer-cement ratio (p/c) and water-cement ratio (w/c) When p/c was 20% and w/c was 40%, the compressive strength of PMM was lower than the un- Fig Trend of Compressive Strength of Acrylic PMM with Different Curing Conditions Table Compressive Strength of Acrylic PMM with Different Curing Conditions Compressive strength (MPa) Code days days 14 days 21 days 28 days 90 days Compressive strength (MPa) 180 days year Code days days 14 days 21 days 28 days 90 days 180 days year UM050d 16.8 21.7 28.4 32.0 33.4 34.9 35.6 36.2 UM050h2 19.1 24.6 30.3 33.0 34.3 35.1 35.7 35.9 AE1-0535d 19.0 26.5 33.5 36.7 37.8 39.8 41.0 41.5 AE2-0535d 19.2 26.7 33.5 36.4 37.1 38.9 40.2 41.0 AE1-0535h2 19.7 26.0 32.1 34.7 35.6 36.5 37.2 37.4 AE2-0535h2 20.1 27.0 32.4 34.6 35.2 35.8 36.7 37.2 AE1-0540d 19.6 26.2 32.2 35.1 36.4 38.4 39.0 39.6 AE2-0540d 20.0 27.2 34.0 37.1 38.0 40.1 41.3 41.9 AE1-0540h2 19.9 25.3 30.5 32.9 33.8 34.8 35.1 35.5 AE2-0540h2 20.5 26.6 32.3 35.0 35.6 36.6 37.5 37.9 AE1-1030d 19.6 27.4 34.1 37.4 38.5 40.6 41.3 42.1 AE2-1030d 21.0 27.4 34.3 37.5 38.7 40.8 42.0 42.9 AE1-1030h2 20.4 27.0 32.8 35.4 36.0 37.2 37.6 38.0 AE2-1030h2 22.1 27.8 33.3 35.8 36.7 37.7 38.6 39.2 AE1-1035d 20.4 28.6 36.5 40.1 41.0 43.2 44.1 44.7 AE2-1035d 21.5 28.6 35.9 39.1 40.6 42.7 43.4 43.8 AE1-1035h2 20.7 27.8 34.6 37.5 38.0 39.0 39.5 39.8 AE2-1035h2 22.1 28.0 34.1 36.8 37.8 38.8 39.2 39.4 AE1-1040d 19.3 25.6 32.7 35.8 36.6 38.7 39.3 39.8 AE2-1040d 19.5 27.2 33.8 36.6 37.5 39.2 40.1 40.8 AE1-1040h2 18.8 24.3 30.6 33.1 33.5 34.8 34.9 35.2 AE2-1040h2 19.2 26.0 31.8 34.1 34.5 35.4 35.8 36.3 AE1-1527d 23.0 30.7 37.6 40.8 42.3 44.8 46.1 46.8 AE2-1530d 21.5 29.8 37.2 40.0 41.2 43.3 44.2 45.3 AE1-1527h2 23.8 29.5 35.6 38.2 39.3 40.7 41.3 41.6 AE2-1530h2 22.4 29.2 35.4 37.8 38.6 39.3 39.8 40.5 AE1-1535d 19.5 26.8 33.0 35.5 36.2 37.8 38.7 39.6 AE2-1535d 20.4 27.3 35.2 38.6 39.7 41.3 42.0 42.6 AE1-1535h2 19.0 25.6 30.8 32.8 33.2 33.9 34.4 34.9 AE2-1535h2 20.0 26.3 33.0 35.8 36.8 37.3 37.6 38.0 AE1-1540d 17.2 22.6 28.3 30.8 31.4 32.7 33.3 34.2 AE2-1540d 18.3 26.0 32.8 35.3 36.2 37.8 38.5 39.1 AE1-1540h2 16.4 21.3 26.2 28.2 28.5 29.1 29.3 29.8 AE2-1540h2 17.6 24.7 30.6 32.6 33.1 33.8 34.1 34.5 AE1-2024d 21.5 28.2 34.8 38.1 39.6 41.7 43.3 43.9 AE2-2030d 21.1 29.3 35.5 38.0 38.5 40.4 41.3 42.2 AE1-2024h2 21.1 27.1 32.9 35.6 36.7 37.6 38.7 38.9 AE2-2030h2 20.7 28.1 33.3 35.4 35.8 36.4 36.8 37.3 AE1-2035d 16.3 21.7 27.6 30.1 31.0 32.2 33.0 33.3 AE2-2035d 18.3 23.8 29.8 32.5 33.4 34.5 35.0 35.5 AE1-2035h2 15.6 20.4 25.4 27.3 28.0 28.5 29.0 29.1 AE2-2035h2 17.7 22.5 27.6 29.7 30.4 30.9 31.2 31.5 AE1-2040d 14.6 19.9 24.7 26.5 27.4 28.4 29.0 29.4 AE2-2040d 15.7 21.2 26.5 28.7 29.4 30.5 31.0 31.4 AE1-2040h2 13.7 18.4 22.4 23.9 24.6 24.9 25.2 25.4 AE2-2040h2 14.9 19.8 24.4 26.1 26.6 27.0 27.3 27.5 Vol 13, No / January 2009 − 25 − Hyug-Moon Kwon, Thuy Ninh Nguyen, and Tuan Anh Le Fig Reduced Ratio of Compressive Strength of PMM in High Temperature and High Humidity modified mortar (Table 4) because too much water was used for hydrating the cement The early 3-day compressive strength of PMM in cyclic curing was higher than in normal condition However, the later compressive strength of PMM in cyclic curing condition was lower than PMM in normal condition (Fig 4) The reduced ratio of compressive strength (the ratio by compressive strength in cyclic curing conditions to the compressive strength for normal condition) was changed adversely according to the age of PMM The reduced ratio was found to be more than 1.0 in the first few days when p/c was from 5% to 10% When the ages of PMM were over days, the reduced ratio was less than 1.0 and decreased with curing time The higher the p/c was, the higher the reduced ratio was (Fig 5) 3.2 Tensile Strength The results of tensile strength of acrylic PMM were shown in Figs and The tensile strength of unmodified mortar in cyclic curing conditions was higher than in the normal condition during the first days after casting but, beyond the age of one week, the strength changed slowly Fig Trend of Tensile Strength of Acrylic PMM with Different Curing Conditions Fig Reduced Ratio of Tensile Strength of PMM in High Temperature and High Humidity − 26 − KSCE Journal of Civil Engineering Improvement of the Strength of Acrylic Emulsion Polymer-modified Mortar in High Temperature and High Humidity by Blast Furnace Slag After months, the tensile strengths of unmodified mortar in both curing conditions were nearly the same The early 3-day tensile strength of PMM in curing cycles was higher than in normal condition However, the later tensile strength of PMM in cyclic curing conditions was lower than PMM in normal condition (Fig 6) The reduced ratio of tensile strength was observed similar to the reduced ratio of compressive strength (Fig 7) 3.3 Flexural Strength The results of flexural strength of PMM were shown on Figs and Similar to the results of compressive strength and tensile strength, Fig showed that the flexural strength of unmodified mortar in curing cycles was higher than in normal condition during the first days after casting but, over the age of one week, the situation changed slowly After months, the flexural strengths of specimens for both curing conditions were nearly the same The early 3-day flexural strength of PMM in cyclic curing condition was higher than 3-day early flexural strength of PMM in normal condition However, the later flexural strength of PMM in cyclic curing condition was lower than PMM for normal condition The reduced ratio of flexural strength (the ratio by flexural strength in cyclic curing conditions to the flexural strength for normal condition) was changed adversely to the age of PMM The reduced ratio was found to be more than 1.0 in the first few days when p/c was from 5% to 10% The reduced ratio of flexural strength of mix proportion with 20% polymer and w/c = 0.35 was lowest in this study When the ages of PMM were over days, the reduced ratio decreased over time (Fig 8) Similar to the reduced ratios of compressive strength and tensile strength, the reduced ratio of flexural strength decreased proportionally with p/c and time (Figs 5, and 9) It was observed that increasing the temperature of curing will speed up the chemical reactions of hydration and thus it has beneficial effects to the early strength of mortar or concrete Although a higher temperature during placing and setting increases the very early strength, it may adversely affect the strength from about days onwards The explanation was that a rapid initial hydration appears to form products of a poorer physical structure, probably more porous, so that a proportion of the pores will always remain unfilled (Neville, 1996) In polymer-modified mortar, both cement hydration and polymers phase formation by the coalescence of polymer particles proceed well to yield a monolithic matrix phase with a network structure in which the cement hydrate phase and polymer interpenetrate into each other, and aggregates were bound by such a Fig Trend of Flexural Strength of Acrylic PMM with Different Curing Conditions Fig Reduced Ratio of Flexural Strength of PMM in High Temperature and High Humidity Vol 13, No / January 2009 − 27 − Hyug-Moon Kwon, Thuy Ninh Nguyen, and Tuan Anh Le co-matrix phase (Tobing, 2000) The strength of polymermodified mortar was affected by various factors that tend to interact with each other: the natural materials, the control factors for mix proportions, curing method and testing method Under hot-dry curing condition, polymer and polymer modified repair materials exhibit improved strength, permeability, diffusion and shrinkage properties when compared to conventional cementitious repair mortars (Hassan, 2000) However, Mirza et al showed that the wet curing condition had an adverse effect on the compressive strength of polymer-modified mortar (Mirza, 2002) Acrylic latex polymers were made from copolymer of acrylates or methyl acrylates with irregular structure This irregular structure prevents the co-location order of polymer chains and forms a tough, flexible polymer with both elasticity and plasticity Thus, long-term exposure to heat and light should first induce thermal degradation or photolysis of ester radicals and methyl on the side chain, then irregular rupture of molecular groups on the main chain would subsequently occur (Ding, 2006) The decreasing strength of polymer-modified mortar in high temperature and high humidity was very clear The strength decreased from 9% to 14% (Figs 5, and 9) The results show that high temperature and high humidity has an adverse effect on the strength of polymer-modified mortar 3.4 Improvement of the Strength Fifteen percent by weight of cement was replaced by BFS in Table Compressive Strength of PMM with and without BFS in Cyclic Curing Conditions Compressive strength (MPa) Code Compressive strength (MPa) days days 14 days 21 days 28 days 90 days 180 days year 19.1 24.6 30.3 33.0 34.3 35.1 35.7 AE1-0535BFS 18.6 24.8 31.9 35.7 37.1 38.4 AE1-0535h2 19.7 26.0 32.1 34.7 35.6 AE1-1030BFS 19.4 26.8 33.6 36.4 AE1-1030h2 UM0050h2 Code days days 14 days 21 days 28 days 90 days 180 days year 35.9 UM0050BFS 18.0 23.7 29.7 33.1 34.9 36.0 36.6 37.1 39.3 40.1 AE2-0535BFS 19.4 26.8 33.3 35.8 36.7 38.5 39.2 39.8 36.5 37.2 37.4 AE2-0535h2 20.1 27.0 32.4 34.6 35.2 35.8 36.5 37.2 37.8 39.3 40.4 41.2 AE2-0540BFS 20.3 26.3 33.3 35.9 37.2 38.7 39.5 40.3 20.4 27.0 32.8 35.4 36.0 37.2 37.6 38.0 AE2-0540h2 20.5 26.6 32.3 35.0 35.6 36.6 37.5 37.9 AE1-1035BFS 21.5 28.6 35.4 37.9 38.5 40.6 42.0 42.9 AE2-1035BFS 21.8 27.8 35 38.9 40.5 41.6 42.2 42.9 AE1-1035h2 20.7 27.8 34.6 37.5 38 39.0 39.5 39.8 AE2-1035h2 22.1 28.0 34.1 36.8 37.8 38.8 39.2 39.4 AE1-1527BFS 22.5 30.1 37.0 40.1 41.5 43.0 44.1 44.8 AE2-1530BFS 22.0 29.1 36.4 40.2 41.9 43.2 44.9 45.5 AE1-1527h2 29.5 35.6 38.2 39.3 40.7 41.3 41.6 AE2-1530h2 22.4 29.2 35.4 37.8 38.6 39.3 40.0 40.5 23.8 AE1-1535BFS 18.4 24.9 31.0 34.0 35.6 37.2 38.1 38.8 AE2-1535BFS 19.6 26.0 33.7 37.5 39.0 40.3 41.1 41.4 AE1-1535h2 19.0 25.6 30.8 32.8 33.2 33.9 34.4 34.9 AE2-1535h2 20.0 26.3 33.0 35.8 36.8 37.3 37.6 38.0 AE1-2024BFS 20.9 27.6 34.2 37.5 39.0 40.4 41.6 42.3 AE2-2025BFS 21.9 28.2 35.0 38.5 40.0 42.4 43.5 44.2 AE1-2024h2 21.1 27.1 32.9 35.6 36.7 37.6 38.7 38.9 AE2-2025h2 22.1 28.6 34.9 37.2 38.0 38.6 39.6 40.0 AE1-2035BFS 15.1 20.1 25.7 28.6 29.9 30.8 31.5 31.9 AE2-2035BFS 17.2 22.3 28.2 31.0 31.9 32.6 33.0 33.6 AE1-2035h2 20.4 25.4 27.3 28.0 28.5 29.0 29.1 AE2-2035h2 17.7 22.5 27.6 29.7 30.4 30.9 31.2 31.5 15.6 Fig 10 Compressive Strength of PMM with and without BFS in Cyclic Curing Conditions − 28 − KSCE Journal of Civil Engineering Improvement of the Strength of Acrylic Emulsion Polymer-modified Mortar in High Temperature and High Humidity by Blast Furnace Slag Fig 11 Tensile Strength of PMM with and without BFS in Cyclic Curing Conditions Fig 12 Flexural Strength of PMM with and without BFS in Cyclic Curing Conditions mix proportion to improve the compressive strength of PMM (Table 5; Fig 10) When 15 % cement was replaced by BFS, the early age of compressive strength of PMM containing BFS (fill color markers in Fig 10) was lower than the early age of compressive strength of PMM without BFS (un-fill color markers in Fig 10) The compressive strength of PMM with BFS was nearly the same without BFS at 14 days However, after 14 days in cyclic curing conditions, the compressive strength of PMM with BFS was higher than PMM without BFS (Fig 10, focus parts) The development of tensile strength and flexural strength was similar to compressive strength The early age of tensile strength and flexural strength of PMM containing BFS were lower than PMM without BFS in cyclic curing conditions The development of later age of tensile/flexural strength of PMM containing BFS was higher than PMM without BFS The significant effect of BFS on tensile/flexural strength of PMM was observed (Table 5; Figs 11 and 12) The improved ratios (ratio by strength of PMM with BFS to the strength of PMM without BFS) of 15% polymer (series AE15BFS) and 20% polymer (series AE-20BFS) were higher than for the 5% polymer (series AE-05BFS) and 10% polymer (series AE-10BFS) The improved ratio of PMM was higher than the Vol 13, No / January 2009 Fig 13 Improved ratio of Compressive Strength of PMM with BFS in Cyclic Curing Conditions unmodified mortar (Figs 13, 14 and 15) The improved ratio of PMM with BFS increases over time In this study, the improved ratio of PMM with BFS increased from to 12% When BFS was used instead of cement, it was for the purpose of increasing SiO2 The molecular density of SiO2 was increased so that it was easy to have the electric bond and ionic bond between SiO2 and positive ions Ca2+ and polymer molecular (Ohama, 1995) The − 29 − Hyug-Moon Kwon, Thuy Ninh Nguyen, and Tuan Anh Le between the strength of polymer-modified mortar of specimens in cyclic curing conditions and in normal condition depended on the polymer-cement ratio in mix proportions It decreases over time The higher the polymer ratio was used, the lower reduced ratio was observed • The replacement of 15% cement by BFS can improve the strength of PMM in high temperature and high humidity The improved ratio of PMM with BFS was higher than for the unmodified mortar with BFS The improved ratio of PMM with BFS increased over time • BFS improved the strength of PMM from to 12% Fig 14 Improved Ratio of Tensile Strength of PMM with BFS in Cyclic Curing Conditions Fig 15 Improved Ratio of Flexural Strength of PMM with BFS in Cyclic Curing Conditions aggregate surface bonding was increased by the reaction of SiO2 and Ca2+ and polymer molecules Moreover, the fineness of BFS was very small, so that they were able to fill the pores in the structure of PMM Conclusions • High temperature and high humidity has an adverse effect on the strength of polymer-modified mortar The strength of polymer-modified mortar in cyclic curing conditions was lower than for normal condition The strength of polymer-modified mortar in cyclic curing conditions increased less than in normal condition after 28 days • The strength of PMM in cyclic curing conditions was higher than for normal condition at first days The reduced ratio References ASTM C 109/C109M-99 ASTM C 348-97 ASTM C 496-96 Chandra, S and Ohama, Y (1994) Polymers in concrete, CRC Press, Inc Ding, S.H., Liu, D.Z., and Duan, L.L (2006) “Accelerated aging and aging mechanism of acrylic sealant.” Polymer Degradation and Stability, Vol 91, pp 1010-1016 Hassan, K.E., Robery, P.C., and Al-Alawi, L (2002) “Effect of hot-dry curing environment on the intrinsic properties of repair materials.” Cement and Concrete Composites, Vol 22, pp 453-458 Hassan, K.E., Brooks, J.J., and Alawi, L.A (2001) “Compatibility of repair mortars with concrete in a hot dry environment.” Cement and Concrete Composites, Vol 23, pp 93-101 Information Center of Natural Resources and Environment, Ministry of Resources and Environment http://www.ciren.gov.vn/index.php?newlang=englwash Jenni, A., Zurbriggen, R., Holzer, L., and Herwegh, M (2002) “Changes in microstructure and physical properties of polymermodified mortars during wet storage.” Cement and Concrete Research, Vol 36, pp 79-90 Mirza, J., Mirza, M.S., and Lapointe, R (2002) “Laboratory and filesd performance of polymer-modified cement based repair mortars in cold climates.” Construction and Building Materials, Vol 16, pp 365-374 Neville, A.M (1996) Properties of concrete, 4th and Final Ed., John Wiley & Son, Inc Ohama, Y (1995) Handbook of polymer modified concrete and mortars, Noyes Publications Ru, K., Zhang, D., and Song, J.M (2002) “Properties of polymer modified cement mortar using pre-enveloping method.” Cement and Concrete research, Vol 32, pp 425-429 Tobing, S.D and Klein, A (2000) “Mechanistic studies in Tackified acrylic emulsion pressure 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Engineering Improvement of the Strength of Acrylic Emulsion Polymer- modified Mortar in High Temperature and High Humidity by Blast Furnace Slag After months, the tensile strengths of unmodified mortar in. .. Civil Engineering Improvement of the Strength of Acrylic Emulsion Polymer- modified Mortar in High Temperature and High Humidity by Blast Furnace Slag Results and Discussions 3.1 Compressive Strength. .. Compressive Strength of PMM with and without BFS in Cyclic Curing Conditions − 28 − KSCE Journal of Civil Engineering Improvement of the Strength of Acrylic Emulsion Polymer- modified Mortar in High Temperature