Ternary Blended Concrete Research Articles

Effect of relative levels of mineral admixtures on corrosion resistance of cracked ternary cement blend concrete

In recent years, emphasis has shifted from using high strength material to highly durable material, to fulfill the demands of sustainable construction. Concrete made with ternary blend of ordinary Portland cement (OPC), silica fume (SF), and fly ash (FA) is a judicious choice before the construction industry for obtaining highly durable concrete. This paper reports the effect of replacement of OPC by FA (20, 30, 40, and 50% replacement of OPC) and/or SF (7 and 10%) on the mechanical and durability properties at w/ b ratio of 0.3 and 0.4. The influence of crack and crack width on half-cell potential (HCP) measurement, conducted on uncracked and cracked specimens, was studied, which showed that ternary cement blend concrete was superior to OPC concrete even in cracked condition. As crack width increases, the HCP readings tend to be more negative, indicating higher probability of corrosion activity.

An Artificial Neural Networks Model for Predicting Permeability Properties of Nano Silica–Rice Husk Ash Ternary Blended Concrete

In this study, a two-layer feed-forward neural network was constructed and applied to determine a mapping associating mix design and testing factors of cement–nano silica (NS)–rice husk ash ternary blended concrete samples with their performance in conductance to the water absorption properties. To generate data for the neural network model (NNM), a total of 174 field cores from 58 different mixes at three ages were tested in the laboratory for each of percentage, velocity and coefficient of water absorption and mix volumetric properties. The significant factors (six items) that affect the permeability properties of ternary blended concrete were identified by experimental studies which were: (1) percentage of cement; (2) content of rice husk ash; (3) percentage of 15 nm of SiO2 particles; (4) content of NS particles with average size of 80 nm; (5) effect of curing medium and (6) curing time. The mentioned significant factors were then used to define the domain of a neural network which was trained based on the Levenberg–Marquardt back propagation algorithm using Matlab software. Excellent agreement was observed between simulation and laboratory data. It is believed that the novel developed NNM with three outputs will be a useful tool in the study of the permeability properties of ternary blended concrete and its maintenance.

Effect of Water-to-Binder Ratio, Air Content, and Type of Cementitious Materials on Fresh and Hardened Properties of Binary and Ternary Blended Concrete

The purpose of this study is to investigate the effects of water-to-binder ratio (w/b), air content, and type of cementitious material on the fresh and hardened properties of binary and ternary blended concrete mixtures in pavements. This experimental program prepared a total matrix of 54 mixtures with w/b of 0.40 and 0.45; nominal air content of 2, 4, and 8%; and three types of supplementary cementitious materials and one ordinary portland cement in different combinations. Binder systems included ordinary portland cement, binary mixtures with slag cement, Classes F and C fly ash, and ternary mixtures containing a combination of slag cement and one type of fly ash. Workability, total air content, air void system parameters (i.e., spacing factor and specific surface) in fresh concrete, setting time, compressive strength, surface resistivity, and shrinkage were determined. Test results showed that ternary mixtures followed the trends of their constituent materials. Binary and ternary mixtures containing Class C fly ash and slag cement exhibited higher compressive strength than the control mixture. The surface resistivity and shrinkage results of binary and ternary mixtures were equal to or improved over the control mixture.

Influence of 15 and 80 nano-SiO2 particles addition on mechanical and physical properties of ternary blended concrete incorporating rice husk ash

This study demonstrates the effects of SiO2 nanoparticles as additives with two different sizes of 15 and 80 nm on compressive strength and porosity of rice husk ash (RHA) blended concrete. Up to 20% of ordinary Portland cement (OPC) was replaced by RHA with average particle size of 5 micron. Also, SiO2 nanoparticles were added to the above mixture at four different weight percentages of 0.5, 1.0, 1.5 and 2.0 and cured in lime solution. The results indicated that compressive strength of Portland cement–nano SiO2–rice husk ash (PC–NS–RHA) ternary blended concrete was considerably increased. Moreover, the total amount of porosity decreased to a minimum with respect to the control concrete. This improvement was observed at all the curing ages and replacement levels, but there was a gain in the optimal point with 20% of RHA plus 2% of 80 nm SiO2 particles at 90 days of curing.

Drying shrinkage of ternary blend concrete in transportation structures

Shrinkage can be a major problem in transportation structures; shrinkage-associated cracking often leads the way to further durability problems such as corrosion and increases maintenance costs. Ternary cementitious blends are used in today’s transportation structures in order to obtain high-performance concrete mixes. Drying shrinkage behavior of ternary blend concretes used in the transportation infrastructure was studied and the findings are presented. Four bridge deck and one pavement mixes, in which supplementary cementitious material constitutes up to 50% of the total cementitious amount, were tested for both restrained and unrestrained shrinkages. The results indicate that shrinkage strain rate linearly increases with cementitious material content, paste-to-void ratio (by volume), and clay content of fine aggregate. Chemical admixtures (e.g. water reducer quantity) also appear to be another aggravating factor.

Water absorption control of ternary blended concrete with nano-SiO2 in presence of rice husk ash

In the current study, the effects of SiO2 nanoparticles as additive with two different sizes of 15 and 80 nm on water absorption of rice husk ash (RHA) blended concrete have been investigated. Concrete samples were prepared by replacing 10, 15 and 20 wt% of cement with RHA and 0.5, 1.0, 1.5 and 2.0% of cement with SiO2 nanoparticles followed by curing in lime solution for 7, 28 and 90 days. The results indicated that the resistance to water absorption of Portland cement–nano SiO2–rice husk ash (PC–NS–RHA) ternary blended concrete was considerably improved with respect to the control concrete. This improvement was observed at all curing ages and replacement levels but the optimal point was reached for 20% of RHA incorporating 2% of 80 nm SiO2 particles at 90 days of curing. Fast formation of C–S–H gel in the presence of ultra high active nano-sized SiO2 and micron level RHA particles together with their high filler effect may result in a continuous cement paste with the lowest weak zones. It has been concluded that the use of novel ternary blended concrete (PC–NS–RHA) provides significant reduction in the water absorption of concrete.

Assessment of methods for optimising ternary blended concrete containing metakaolin

The relative effectiveness of three approaches—isothermal calorimetry, trial batching and particle packing models—for optimising mix proportions in Portland cement/metakaolin (MK)/fly ash (FA) ternary blended concretes was compared through measurements of workability and compressive strength, in consideration of economy. Mixtures were prepared using single cement and class C FA and two MKs of varying fineness. The finer MK showed a higher rate of reaction, but the isothermal calorimetry also suggested that MK replacements of 5% or higher are needed to overcome the hydration delay resulting from the use of 25% by mass FA. Trial batches at three water-to-cementitious materials ratios (w/cm)—0·30, 0·40 and 0·50—were designed based on the calorimetry results. While workability decreased with increasing MK content, similar or better workability than the control mixes was achieved in the ternary blends. The compressive strength significantly increased with increasing MK content, as compared to the ordinary concrete and the FA binary blends, and especially at low w/cm (i.e. w/cm = 0·30). The trial batch strength results confirmed that the hydration rates (measured by isothermal calorimetry) could be used to optimise binder composition for early concrete strength. However, in the third approach, the particle packing model was found to be insufficiently related to measured 1-day strength or to strength in higher w/cm concrete; the closest relationship between the primary model parameter (q) and strength was found at lower w/cm and at later ages (i.e. 28 days). It is proposed that the lack of consideration of the constituent's chemical reactivity of highly reactive materials, such as MK, makes this approach unreliable at early ages and at higher w/cm. Finally, despite the lack of correlation between q and strength, results show q values of 0·26-0·29 are optimal for workability.

삼성분계 혼합콘크리트의 염화물 침투 저항성 및 내구성에 대한 고찰

Mineral admixtures are used to improve the quality of concrete and to develop sustainability of concrete structures. Supplementary cementitious materials (SCM), such as silica fume (SF), granulated blast furnace slag (GGBS) and pulverized fly ash (PFA), are gradually recognized as useful mineral admixture for producing high performance concrete. The study on ternary blended concrete utilizing mainly three major mineral admixtures is limited and the study on durability and chloride induced corrosion resistance of ternary blended concrete is very few. This study examines the durability characteristics of the ternary blended concrete composed of different amount of the SCM with ordinary Portland concrete and the study experimentally focuses on corrosion resistance evaluation of ternary blended concrete subjected to chloride attack. In this study, 50% replacement ratio of mineral admixture to OPC was used, while series of combination of GGBS, SF and PFA binder were used for chloride corrosion resistance test. This study concerned the durability properties of the ternary blended concrete including the corrosion resistance, chloride binding, chloride transport and acid neutralization capacity. It was found that the ternary blended concrete utilizing the SCM densified the pore structures to lower the rate of chloride transport. Also, increased chloride binding and buffering to acid were observed for the ternary blended concrete with chlorides in cast.

Ternary blended cement concrete. Part I: early age properties and mechanical strength

While there is ample information in the literature on the mechanical performance and durability of concrete made with either limestone or granulated blast furnace slag,very little is known about the effect of the combined action of these two additions on concrete properties. The present paper evaluates the early stage properties and mechanical strength of binary and ternary cement concrete containing up to 18% limestone and 20% granulated blast furnace slag. The results show that the use of ternary cements has no substantial effect on concrete setting time, although it does reduce bleeding and enhance mechanical strength with respect to unadditioned Portland and/or binary cement concrete.

Durability of Ternary Blend Concrete with Silica Fume and Blast-Furnace Slag: Laboratory and Outdoor Exposure Site Studies

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Strength development of slag and ternary blend concrete

Ground granulated blast furnace (GGBF) slag is increasingly used in concrete construction due to its technical and economic benefits. This paper describes the strength development of 3 grades of plain cement concretes, portland blast furnace slag (slagment) concretes and concretes in which 15 and 35% of slagment was replaced by flyash (ternary blends). These concretes were cured in standard and nonstandard curing conditions using standard and nonstandard cylindrical specimens. The straight replacement of portland cement by slagment (65% cement and 35% slag) gave higher strength for low to medium strength concretes (20 and 35 MPa). The results also suggest that the strength of the concretes made with slagment was less affected under inadequate curing conditions as compared to the strength of the plain cement concretes. It was also found that the indicated strength of the smaller cylinders (75×150 mm) was adversely affected in the drying curing regimes whereas it was only marginally different from the strength of 150×300 mm cylinders under continuous fog curing. For all the concretes tested, initial curing for 7 days seems to be the most appropriate as it is both practicable and gives adequate strength.