Silica Fume Replacement Ratio Research Articles

Ion transport mechanism and diffusion model establishment in recycled aggregate concrete subjected to magnesium, sulfate, and chloride attack

Recycled aggregate concrete (RAC), which is used in Northwest China, is inevitably subjected to various aggressive environments. However, the aggressive ions of chloride, sulfate, and magnesium and the original ions of calcium and hydroxide in RAC under the combined action of magnesium-sulfate-chloride attack and dry–wet (D&W) cycles have received little attention in previous studies. Therefore, in this study, the content of aggressive and original ions in exposed RAC was quantified, and the influence of the replacement ratio of supplementary cementitious materials (SCMs) on diffusion was investigated. Results showed that the contents of chloride, sulfate, and magnesium in exposed RAC increased with an increase in the replacement ratio of silica fume (SF) and metakaolin (MK). In contrast, the contents decreased with the increase in the replacement ratio of granulated blast furnace slag (GBFS). At the same exposure time and depth, the content of RAC with ternary cementitious materials from the highest to the lowest was in the order of cement–fly ash –SF, cement–fly ash–MK, and cement–fly ash–GBFS. Visual appearance, relative compressive strength, and the diffusion coefficient exhibited a similar change law. An exponential relationship was observed between the diffusion and time delay coefficients and the replacement ratio of SCMs, and the content of aggressive ions on the exposed surface decreased linearly with increasing exposure time. Diffusion models of aggressive ions were established to consider the multiple effects. Aggressive ion–original ion interaction influenced the mineral phases’ composition in the corrosive zone and led to a difference in the diffusion process and depth.

Orthogonal experimental design for compressive strength of recycled coarse aggregate concrete with silica fume-slag-fly ash hybrid micro-powders

Recycled Coarse Aggregate Concrete (RAC) is a type of concrete that uses recycled coarse aggregate (RCA) instead of natural coarse aggregate (NCA), which helps to reduce the negative environmental impact of construction waste. In order to improve the low compressive strength of RAC and solve the problem of shortage of natural aggregates, this paper develops a high-performance concrete called recycled coarse aggregate concrete with silica fume-slag-fly ash hybrid micro-powders (HMRAC) by replacing part of the cement with a mixture of micronized silica fume (SF), slag (SG) and fly ash (FA) and using RCA of 50% mass instead of NCA. The optimum combination parameters and prediction model for the compressive strength of HMRAC were also proposed by orthogonal experimental design. A constant water-cement ratio of 0.45 and a 50% mass replacement of natural coarse aggregate (NCA) by recycled coarse aggregate (RCA) were adopted in the experiment, and the mass replacement ratios of silica fume (SF), slag (SG), and fly ash (FA) for ordinary Portland cement (OPC) were used as the test variables. In total, 16 combinations were tested, including a control group where 50% of the NCA mass was replaced by RCA. First, we investigated the degree and significance of the effect of the mass substitution ratio of SF, SG, and FA on the compressive strength of HMRAC using analysis of variance (ANOVA) and extreme difference analysis. Then, we determined the optimal combination ratio of SF, SG, and FA. Secondly, multiple regression analysis was used to propose a multiple regression model for predicting the compressive strength of HMRAC. Finally, we computed and analyzed the carbon emissions of HMRAC. The results indicated that the mass substitution rates of FA and SG had a greater effect on the compressive strength, and the mass substitution rate of SF had a lesser effect on the compressive strength. The interaction of SF, SG, and FA can significantly enhance the compressive strength of RAC. The optimal compressive strength performance of HMRAC was observed when the proportions were as follows: SF constituted 10%, SG made up 15%, and FA accounted for 5%. The regression model has reasonable accuracy and a small standard deviation of residuals. It can effectively predict the compressive strength value of HMRAC, aligning well with the experimental results. It exhibits a superior carbon reduction rate of 21.90%, compared to conventional concrete.

Influence of mix proportioning parameters and curing regimes on the properties of ultra-high strength alkali-activated concrete

This study investigates the influence of mix proportioning parameters and curing regimes on the material properties of alkali-activated binder-based ultra-high strength concrete (AAB-UHSC). The effects of five groups of mix proportioning parameters (i.e., fly ash replacement ratio, silica fume replacement ratio, alkali to binder ratio, water glass modulus, and steel fiber content) and three curing regimes(i.e., ambient curing, standard curing, and hybrid curing) on the workability, compressive strength, flexural strength and microstructure development of AAB-UHSC were systematically evaluated. The results indicated that increasing the steel fiber and silica fume dosage negatively affected the flowability of freshly mixed AAB-UHSC. There existed an optimal alkali-to-binder ratio and water glass modulus in terms of flowability, compressive strength, and flexural strength, but the fly ash replacement ratio had a complex effect on the material performance of the AAB-UHSC. The microstructures of the specimens cured in hybrid curing regimes were denser, and fewer cracks were observed, which resulted in higher strength compared to specimens cured under ambient curing and standard curing conditions. The three types of curing regimes adopted barely alter the phases and molecular bonds of hydration products based on the XRD and FTIR results. In addition, the correlations between the compressive strength of the AAB-UHSC obtained under ambient curing conditions, standard curing conditions, and obtained under hybrid curing and standard curing conditions were analyzed, and the fitted results had higher correlation coefficients (R2).

Investigation of the Effect of Seawater and Sulfate on the Properties of Cementitious Composites Containing Silica Fume

Concrete consumes over two billion tons of freshwater every year and 75 % of regions of the world will become water shortages in 2050. Because of increasing freshwater scarcity seawater may become reasonable as an alternative mixing and curing water for concrete. In this study, seawater (SW) was utilized for mixing and curing of concrete and investigated the seawater and sulfate on the properties of cementitious composites containing silica fume (SF). Hence, SF was replaced with the cement at ratios corresponding to 0 %, 2.5 %, 5 %, 7.5 %, 10 %, 12.5 %, and 15 % by weight of cement, and SW and tap water (TW) were used as mixing water in the production of cementitious composites. Thus, the effect of SW on the properties of fresh cement pastes and the flexural and compressive strengths of 7-day, 28-day, and 90-day old cementitious composites were examined. Additionally, the lengthening change values of cementitious composites containing SF that were kept in 5 % Na2SO4 solution for 7-day, 28-day, and 90-day were determined. The SF delayed the setting period while increasing the water requirement of the cement paste. It is determined that the SW accelerated the setting period of cement. In the case when 10 % SF in cementitious composites was used, the maximum compressive and flexural strengths were obtained for cementitious composites produced by mixing with SW and SF fume at an age corresponding to 28-day and 90-day. It was observed that the length change of the cementitious composites decreased due to the increase in the SF replacement ratio.

Reduction of computational error by optimizing SVR kernel coefficients to simulate concrete compressive strength through the use of a human learning optimization algorithm

This research presents a new model for finding optimal conditions in the concrete technology area. To do that, results of a series of laboratory investigations on concrete samples were considered and used to design several artificial intelligence (AI) models. The data samples include 8 parameters i.e., silica fume replacement ratio, fly ash replacement ratio, fine aggregate, water content, high rate water reducing agent, coarse aggregate, total cementitious material, and age of samples, were used to predict and optimize the compressive strength of concrete samples. For optimization purposes, this study used a human learning optimization (HLO) algorithm to find the optimal results as well as optimizing the kernel coefficients of the support vector regression (SVR) models. Initially, to form the core of this research, various models were constructed and proposed to design the required relationship between the data using SVR. Since different SVR kernels have their own coefficients, using optimization theory, the probability of error in the models was reduced and the models were identified and executed with the highest accuracy. Finally, the polynomial model was selected as the model with the lowest computational error and the highest accuracy for evaluating the compressive strength of the concrete samples. The accuracy of the proposed SVR model for training and testing data was obtained as the coefficient of determination (R2) = 0.9694 and R2 = 0.9470, respectively. This function was considered as a relation, to be developed by the HLO algorithm to find optimal options under different conditions. The results for 14 samples, which are the most important examples of this research, showed that the optimal states are obtained with a high level of accuracy. This confirms the proper use/develop of the SVR-HLO algorithm in designing the predictive model as well as finding optimal conditions in the concrete technology area.

Understanding hydration heat of mortars containing supplementary cementitious materials with potential to immobilize heavy metal containing waste

Supplementary cementitious materials (SCMs) have been widely used not only in civil engineering concrete components, but also in (nuclear) waste treatment engineering because of their beneficial effects on microstructure, engineering properties and durability of concrete. A comprehensive experimental campaign has been undertaken to investigate the effects of SCMs, which includes silica fume (SF) and blast furnace slag (BFS) in combination with ordinary Portland cement (OPC) on the behaviour of hydration heat evolution during early ages of mortars. The samples with different water/cement (w/c) ratios (0.5, 0.7, 0.9) and replacement ratios of SF (10%, 20%, 30%) and BFS (30%, 50%, 70%) were subjected to isothermal calorimetry tests at various temperatures (20, 30, 40 and 50 °C) in order to assess the effects of SCMs on the rate of hydration heat, cumulative heat release, activation energy and setting times of blended mortars. Knowledge obtained from these blended systems was then applied for cementation of a heavy metal containing waste sludge simulant, where the potential for thermal cracking and delayed ettringite formation due to hydration heat generation is of great concern. Results show that both BFS and SF increase the hydration rate but reduce cumulative heat release compared to pure OPC mortar. The ternary system (OPC:BFS:SF) exhibits different hydration characteristics compared to the binary system (OPC:BFS(or SF)) and there is a slight interaction between BFS and SF. The presence of sludge in the matrix significantly accelerates the hydration process and reduces the apparent activation energy. The role of temperature is more important for mortars containing BFS rather than SF, and less pronounced for the system containing sludge. Estimating the setting times based on the isothermal calorimetry data is more accurate for the final setting time rather than for initial setting time and an overestimation of 10% might occur or even more for the system containing sludge, which is still acceptable taking into account the measurement uncertainty.

Effects of silica fume on physicochemical properties and piezoresistivity of intelligent carbon black-cementitious composites

Carbon black (CB) filled cementitious composites as cement-based sensors with intrinsic piezoresistivity have the potential applications for structural health monitoring (SHM). Effect of silica fume (SF) replacement ratio on the physicochemical, mechanical and piezoresistive properties, and microstructure of CB-cementitious composite were experimentally investigated in this study. The results show that 5% or 10% replacement ratio of SF can improve the water impermeability, setting time and electrical conductivity, but decrease the fresh flowability. Cementitious composite with 10% SF exhibiteds excellent compressive and flexural strengths. Moreover, cement hydration in the acceleration stage decreased with the increase of SF content in the early stage, but the phase analysis after 28 days curing demonstrates that with the addition of SF, there are more hydrated products and less ettringite. In addition, the microstructures of cementitious composites without SF present more porous structures and CB agglomerations. In contrast, the amount of micropores or voids was significantly reduced by the addition of SF due to the physical filling effect and less CB agglomerations. In terms of piezoresistivity, SF can obviously improve the fractional changes of resistivity (FCR) under cyclic compression. With 10% SF, CB-cementitious composites as cement-based sensors exhibited excellent FCR and electrical stability, which will promote their development and application in the SHM for smart infrastructures.

Effect of dispersibility of carbon nanotubes by silica fume on material properties of cement mortars: Hydration, pore structure, mechanical properties, self-desiccation, and autogenous shrinkage

In this study, the effect of dispersibility of carbon nanotubes (CNTs) by silica fume on the material properties of cement mortars were experimentally analyzed. Cement mortar specimens incorporating different proportions of silica fume and CNTs were fabricated, and tests were conducted to measure their hydration kinetics, pore structure, compressive strength, elastic modulus, internal relative humidity, and autogenous shrinkage. Additionally, scanning electron microscopy analysis was performed to observe the morphology of the CNTs in the cement matrix. The results revealed that the dispersibility of the CNTs was enhanced with the increasing replacement ratio of silica fume. Furthermore, well-dispersed CNTs resulted in a decrease in the self-desiccation by varying the pore structure and hydration kinetics, and an increase in the modulus of elasticity, thereby reducing the autogenous shrinkage of the cement mortar specimens.

Applying a meta-heuristic algorithm to predict and optimize compressive strength of concrete samples

The successful use of fly ash (FA) and silica fume (SF) materials has been reported in the design of concrete samples in the literature. Due to the benefits of using these materials, they can be utilized in many industrial applications. However, the proper use of them in the right mixes is one of the important factors with respect to the strength and weight of concrete. Therefore, this paper develops relationships based on meta-heuristic (MH) algorithms (artificial bee colony technique) to evaluate the compressive strength of concrete specimens using laboratory experiments. A database comprising silica fume replacement ratio, fly ash replacement ratio, total cementitious material, water content coarse aggregate, high-rate water-reducing agent, fine aggregate, and age of samples, as model inputs, was used to evaluate and predict the compressive strength of concrete samples. Developed models of the MH technique created relationships between the mentioned parameters. In the new models, the influence of each parameter on the compressive strength was determined. Finally, using the developed model, optimum conditions for compressive strength of concrete samples were presented. This paper demonstrated that the MH algorithms are able to develop relationships that can serve as good substitutes for empirical models.

Investigation on Performance of Concrete Incorporating Silica Fume and Local UAE Materials

In an effort to reduce the amount of cement in the concrete industry and produce greener concrete, emphasis was put on using several industrial by-products such as silica fume, fly ash and slag as partial replacements for cement in concrete. Due to the enormous number of mega reinforced concrete projects constructed in the United Arab Emirates, it is considered to be one of the largest consumers of high strength concrete in the region. On the other hand, only limited research has been done on high strength concrete incorporating local materials in the UAE. The main objective of this research is to conduct an investigation on the performance of high strength concrete containing silica fume as partial replacement of ordinary Portland cement incorporating superplasticizers and local UAE materials by studying its mechanical properties and durability. The experimental program involved two groups: The first group had a water-to-binder material ratio (w/b) of 0.4, whereas, the second group had w/b = 0.3. For both groups the silica fume replacement percentages were 0 (control mix) 5, 7.5, 10, 12.5, and 15 percent. The mechanical properties were tested at 7, 28, and 91 days and the durability tests were performed at 28 days. The results were compared to the control mix and they showed that for all the curing ages studied the use of silica fume as partial replacement of OPC has favorable effect on the compressive strength values and the optimum replacement ratios of silica fume for the tested specimens are found to be at 12.5% and 10% replacement for the w/b ratios of 0.3 and 0.4, respectively. For all the four performed durability tests the replacement of the OPC with silica fume is found to have favorable results and the higher the silica fume percentage replacement of OPC the more favorable the results are. The detailed description of the used mixes and the main conclusions drawn from this research are presented in this paper

Effect of Curing Methods on Compressive Strength of Sustainable Self-Consolidated Concrete

Concrete can only achieve the desired compressive strength and durability if cured properly for a prescribed period. For most building codes, concrete structural components and systems are designed for the 28-day compressive strength. Nonetheless, concrete structures are cured typically for only 3 to 7 days. There is an increasing use of curing techniques that involve chemical compounds such as acrylic-based compounds. The emergence of such techniques requires investigation of their effectiveness, compared to traditional curing methods. This article presents the findings of a study to compare the compressive strength of concrete cured using three methods, namely submersion in water, air curing under elevated temperature, and curing with a chemical compound. Compressive strength was determined on standard 150 mm x 150 mm x 150 mm cubes made of sustainable self-consolidated concrete (SCC) in which 90% of ordinary Portland cement content was replaced with combinations of high volume ground granulated blast furnace slag (GGBS), silica fume, and fly ash. A total of 20 mixes were tested, the first set of 10 mixes prepared with water to be binder (w/b) ratio of 0.33 and the second set of 10 mixes prepared with w/b of 0.36. For all mixes, samples cured under air with 45 °C temperature produced the highest 28-day compressive strength compared to other curing methods. Similarly, concrete samples cured using the chemical compound produced higher compressive strength compared to the traditional curing method. The sustainable SCC mix producing the highest compressive strength of 76.22 MPa under air curing was prepared with w/b of 0.33, 72.5% slag replacement ratio, 12.5% silica fume replacement ratio, 10% fly ash while Portland cement represented only 10% of the total binder content.

Adverse effects of high temperatures and freeze-thaw cycles on properties of HFRHSCs containing silica fume and metakaolin

Adverse effects of high temperatures (HTs) and freeze-thaw (F-T) cycles on the properties of hybrid fibers reinforced high strength concretes (HFRHSCs) containing silica fume (SF) and silica fume + metakaolin (SF + MK) were investigated in this study. Concrete mixtures without and with hybrid fibers (HFs) up to 20% replacement by the weight of Portland cement (PC) with SF and SF + MK were made with the water-binder ratio of 0.25. Experimental studies were conducted on the specimens prepared from these mixtures to determine the ultrasound pulse velocity (Upv), compressive strength (fc), flexural strength (fct,fl) and splitting tensile strength (fct,sp) values of concretes without and with HFs exposed to ambient temperature (AT) and HTs. Moreover, the experimental studies were performed to determine the Upv and fc values of concretes exposed to F-T cycles. Microstructure analyses were also conducted on the specimens to examine the changes in the matrix, interface zone and aggregate of concretes without HFs exposed to AT, HTs and F-T cycles. Experimental results have revealed that replacement ratios of SF and SF + MK have important effects on the properties of concretes without and with HFs. The experimental results have also shown that the fc, fct,fl and fct,sp values of the concretes with HFs are higher than the concretes without HFs. The Upv, fc, fct,fl and fct,sp values of the concretes with HFs have been affected more than that of the concretes without HFs due to the adverse effects of HTs.

Fundamental properties and mechanical characteristics of high performance cement composite with steel fibres under high temperature

High-performance fibre-reinforced cementitious composite (HPFRCC) is characterized by multiple functioning composite materials comprising fibre and cement matrix. HPFRCC is able to withstand tensile stress forming distributed micro-cracks since embedded fibres in concrete are to improve energy-absorption capacity and apparent ductility. This characteristic can be applied to protect structures under an extreme state of loading, such as blast or impact. In order to determine a mix proportion, this study considered various variables in the mix. Following experimental results, this study suggests an optimum mix proportion of HPFRCC and investigated fundamental properties of the considered mixes. Flexural performance is one of the representing characteristics of the high-fracture energy-absorbing materials. This study investigated the flexural performance of HPFRCC, which used high-strength steel fibres with volume fraction 8%. Under ASTM 1609, load–deflection curves were obtained. The major test variables include silica fume replacement ratio 0 and 15% and exposure temperature, ambient and 400 °C. The flexural strength was similar to the compressive strength and the absorbed fracture energy was relatively greater than other typical HPFRCC. This may be a composite reaction of the strong bonding between fibre and matrix and high-compressive strength of the matrix itself.

Experimental study on strength and durability of lightweight aggregate concrete containing silica fume

In this study, the mechanical property and durability performance of high strength lightweight aggregate concrete (LWAC) with silica fume for 91days were presented. LWACs were designed to have the design compressive strength of 60MPa at 28days and the oven-dry density below 1900kg/m3. Nine mixtures with three aggregate types and silica fume replacement ratio of 0%, 3.5% and 7.0% by cement weight were prepared. The splitting tensile strength, the compressive strength and the modulus of elasticity tests were conducted at 7days, 28days, 56days and 91days. The chloride penetration resistance tests were done at 28days, 56days and 91days. The chloride diffusion coefficient based on the measurement of chloride penetration depth was also measured at 7days, 14days, 28days, 56days and 91days. The rapid freeze-thaw cycling tests were conducted and the relative dynamic modulus was evaluated up to 300 cycles. The results indicate that the durability against chemical deterioration for LWAC incorporated to silica fume depends on the compositions of hardened cement pastes in concretes, while the durability against physical attack depends on the types of aggregates.

THE EFFECT OF FIBER DISPERSION ON STRENGTH PROPERTIES OF FIBER-REINFORCED CEMENT COMPOSITES WITH MWCNT

This experimental study was intended to improve the strength properties of Multi-walled Carbon Nano-tubes (MWCNT) reinforced cementitious composites. CNT is a very promising construction material with excellent mechanical properties. However, the strong van der Waals force between their particles hinders their dispersion, limiting strength development. Therefore, homogeneous dispersion is required to obtain enhanced strength of composites by incorporating MWCNT. With this purpose, the variables considered in this study are the level of sonication, the amount of surfactant, the replacement ratio of silica fume, etc. Studies through an optical microscope indicated that the fiber dispersion of CNT was improved with the increase of sonication period, and that compressive strength was enhanced as the degree of sonication increased. When superplasticizer as a surfactant had a SP/CNT ratio of 4∼6, the best improvement in strength was obtained. Silica fume was shown to produce the highest compressive strength at 10% replacement.

MWCNT 보강 시멘트 복합체의 압축강도 향상에 대한 실험적 연구

This experimental study was intended to improve the compressive strength of multi-walled CNT reinforced cementitious composites with efficiency. The variables considered are the degree of sonication, the amount of surfactant, the replacement ratio of silica fume, etc. Optical microscope informed that fiber dispersion of CNT was improved with the increase of sonication time, and the compressive strength was proved to be enhanced as the degree of sonication increased. When superplasticizer as a surfactant had SP/CNT ratio of 4~6, the best improvement in strength was obtained. Silica fume was shown to produce the highest compressive strength at 10% replacement. Microstructure of CNT composites was also analyzed; XRD and SEM results indicated that CNT addition hardly changed hydration products and microstructure, and MIP analysis found the reduction of total porosity as well as the increase of nano-pores with the size of tens of nm instead of the decrease of pore distribution in the region of around 10 μm and 100 nm. The results of microstructure analysis explains that the strength improvement is closely related to physical contribution rather than chemical influence by adding CNT.

Effect of Different Curing Regimes on Shrinkage and Strength Properties of Self-Consolidating Mortars Containing Silica Fume in Different Contents

The aim of this research is to study the effect of different curing regimes on shrinkage and strength properties of self-consolidating mortars (SCM) containing silica fume in different contents. Self-consolidating mortars, as new technology products, are especially preferred for use in architectural elements and the rehabilitation and repair of reinforced concrete structures. SCM can be used in precast architectural elements or cast in place repair of reinforced concrete structures. Therefore, investigation on the effects of different curing methods on key properties of SCMs can be beneficial. The shrinkage and strength properties of SCMs produced at different replacement ratios of silica fume (SF) with cement in different curing regimes were studied, at this paper. SCM mixes were prepared in constant water/powder ratio and cured in four different regimes including water curing (WC), accelerated water curing (AWC), air curing (AC) and aluminum tape sealing (AS). A polycarboxylate-based superplasticizer (SP) was added to the mixtures at different rates by mass of the cementitious materials to have appropriate flowability. Fresh mortars workability was determined using mini slump flow and mini V-funnel tests. All SCM specimens were tested and evaluated for compressive strength, flexural strength and shrinkage. It has been found that different curing regimes have considerable effects on both shrinkage and strength properties of SCM. It can be concluded that aluminum tape sealing and accelerated water curing can be used as effective and successful curing methods particularly where the SCM is used as a repair material or in architectural elements, respectively.

Determination of Compressive Strength of Concrete by Statistical Learning Algorithms

This article adopts three statistical learning algorithms: support vector machine (SVM), lease square support vector machine (LSSVM), and relevance vector machine (RVM), for predicting compressive strength (f c ) of concrete. Fly ash replacement ratio (FA), silica fume replacement ratio (SF), total cementitious material (TCM), fine aggregate (ssa), coarse aggregate (ca), water content (W), high rate water reducing agent (HRWRA), and age of samples (AS) are used as input parameters of SVM, LSSVM and RVM. The output of SVM, LSSVM and RVM is f c . This article gives equations for prediction of f c of concrete. A comparative study has been carried out between the developed SVM, LSSVM, RVM and Artificial Neural Network (ANN). This article shows that the developed SVM, LSSVM and RVM models are practical tools for the prediction of f c of concrete.

An Experimental Study on Mechanical Properties for Ternary High Performance Concrete with Fly-Ash, Blast Furnace Slag, Silica Fume

It is essential that concrete component is made up with aggregate, sand, cement and water. But recently, Public concern is increasing of a variety structure, resource recycle. Also, According to heat of hydration rising, Concrete is making a causative of concrete-crack. Concrete-crack causes a falling-off in quality of concrete. Therefore, high-performance concrete is evaluated by concrete mechanical properties (compressive strength, splitting tensile strength) with different admixture (fixing W/B 34%), fly ash, blast furnace slag, and silica fume replacement ratio (50%, 50%, and 25%).

CSA계 팽창재 및 수축 저감제의 혼입에 따른 UHPCC의 초기 수축 거동 평가

이 연구에서는 실리카퓸 및 수축 저감제, 팽창재, 고성능 감수제의 혼입을 변수로 한 초고성능 시멘트 복합체(UHPCC)의 초기 수축 거동을 평가하기 위하여 화학수축 및 자기수축 실험을 수행하고, 응결 측정 결과와 비교하여 UHPCC의 자기건조 시작 시점에 대하여 분석하였다. 실험 결과, 실리카퓸 및 수축 저감제는 초기 화학수축을 증가시키는 경향을 보였으며, 고성능 감수제는 시멘트와 배합수의 수화 반응을 지연시키고 화학수축을 저감시키는 것으로 나타났다. 수축 저감제와 팽창재를 조합하여 적용한 경우 약 49%의 자기수축 저감 효과를 보였으며, 팽창재는 경화를 촉진 시키는 것으로 나타났다. 또한 UHPCC는 다수의 섬유 혼입과 낮은 물-결합재비에 의해 초결 이전부터 자기건조 현상이 발생하는 것으로 나타났다.