Concrete Paving Mixtures Research Articles

Preliminary Optimization of Concrete Paving Mixtures for Sustainability and Performance

Greater sustainability in concrete construction projects generally requires higher replacement of portland cement clinker-based binder materials with byproduct supple-mentary cementitious materials (SCM’s). There may be serious constructability-related performance side effects of such concrete mixtures, however, including delayed setting, slower strength gain, and increased sensitivity of the mixture to changing temperatures. Related impacts for paving applications may include placement and finishing issues, cracking, surface profile and durability concerns, and various other quality and scheduling implications. Mix designs often require more aggressive chemical admixture use and performance side effects are difficult to predict and manage. A protocol is presented for the evaluation of materials and preliminary optimization of proportions that can help maximize practical SCM use in concrete paving mixtures while approximating the performance of traditional mix designs. An approach using simple thermal profile testing of paste mixtures in the lab is presented and used to show how these influences can be understood and managed.

Replacement of Coarse and Fine Aggregate in Concrete Pavement Mixtures with Recycled Concrete Aggregate

This study considered the effects of recycled concrete aggregate (RCA) as a replacement of both coarse and fine aggregate in concrete. The coarse portion was replaced by 100% RCA and the fine portion was replaced with RCA at various amounts up to 50%. In addition, fly ash and ground granulated blast furnace slag were utilized as partial replacements of cement. All mixtures were prepared using the twostage mixing approach and the coarse and fine RCA were in a partially saturated condition. The use of RCA fine aggregate (RFA) reduced the concrete strength. However, it was found that the concrete can have a statistically similar compressive strength to concrete with 100% coarse RCA and no RFA. The shrinkage for almost all recycled concrete mixes was statistically similar at early ages, but at later ages, concrete containing RFA can potentially shrink more, especially if slag and fly ash are used to replace cement. The findings suggest that, with proper design, both RCA and RFA can be used in concrete pavement applications.

Performance of Concrete Pavement Mixtures with Marginal Aggregates: Laboratory Investigation

Pavement engineers strive to design and construct portland cement concrete (PCC) airfields that are high quality and economical to maintain during their intended lifecycle. When designing concrete mixtures, locally available materials are desired to minimize transportation or processing expenses. Aggregate costs are of significant concern, because aggregate comprises 70% of the mixture volume. To reduce cost, local aggregates of marginal quality may be used in production; however, the use of these materials may reduce concrete quality and pavement performance. A laboratory investigation of 16 different aggregate materials was conducted, where each aggregate’s physical properties were in some way outside of the U.S. military’s specifications. Recycled materials were also included in the analysis because these materials are generally perceived as inferior. Forty-three mixture designs were created, where one mixture component or material property varied from a specified control mixture. Different proportions of each material were considered to test the effect of deviating from current specifications. Compression and flexural strength test specimens were cast for testing at 28 and 90 days, utilizing 850 total specimens. Statistical analyses were used to evaluate the effect of marginal quality aggregates on concrete strength.

Optimization of fly ash and slag binder systems for pavement concrete mixtures in Indiana

This paper summarizes a research study on the optimization of concrete pavement mixtures in Indiana. The goal of this research was to select an optimum (in terms of paste content and the replacement level of pozzolanic materials) composition for two types of mixtures: portland cement mixtures containing Class C fly ash and portland cement mixtures containing ground granulated blast furnace slag (GGBFS). The variables studied included the total volume of paste in the mixture (21 – 25%) and the level of cement replacement by either fly ash (14 – 30% of total weight of cementitious materials) or GGBFS (20 – 40% of total weight of cementitious materials). The water:cementitious materials ratio was kept constant at 0.44 and the total mass of cementitious materials varied from 272 to 323 kg/m3 (458 to 545 lb/yd3) for fly ash mixtures and from 274 to 326 kg/m3 (462 to 550 lb/yd3) for GGBFS mixtures. The test matrix of concrete mixtures was statistically designed, analyzed and optimized using of Response Surface Methodology (RSM) in order to find the most desirable combinations of variables studied. A total of 20 different concretes (including two control, cement-only mixtures) were produced and tested in the laboratory. The optimal mixtures were found to contain, respectively, ~29% of fly ash and ~21% of paste, and ~36% of slag and ~21% of paste. However, in anticipation of potential problems with workability while using variable aggregate sources it is recommended that the proposed paste content be increased to 22% for fly ash and to 23% for slag mixtures.

Monitoring the Durability Issues of Asphalt Concrete Mixtures

The asphalt concrete mixture is prone to environmental issues such as moisture damage and ageing. This may exhibit a great significance in the service performance of asphalt concrete pavement mixtures which may be more susceptible to many types of early distresses throughout its fatigue life. In the present investigation, asphalt concrete mixtures were prepared and compacted with the aid of laboratory roller compaction into a slab samples. optimum binder content was implemented. Extra samples were prepared at higher and lower binder content of 0.5 % (above and below the optimum). Asphalt concrete beam specimens were obtained from the prepared slab samples with the aid of a diamond saw. Part of the Asphalt concrete beam specimens were tested under four point’s repeated flexural stresses after practicing moisture damage while another part was subjected to long term ageing. The rate of change in the flexural strength was monitored and compared among the various testing conditions at 20 ºC environment and under constant micro-strain level of 750. It was observed that the lower flexural strength was observed for moisture damaged specimens while higher flexural strength could be detected for aged specimens as compared with the control mixtures. The binder content exhibits a significant influence on flexural strength of the asphalt concrete specimens since it declines significantly at higher or lower binder content as compared with that of specimens prepared at the optimum.

The Compaction of Energy and Properties of Roller-Compacted Concrete Pavement with Fillers

Abstract This case study aims to investigate the effects of compaction methods on the mechanical behavior of roller compacted concrete pavement (RCCP) mixtures, which consist of the replacement of different cement by 0%, 5%, and 10% limestone by volume fraction and which were compacted by two compaction methods. These methods are commonly discussed in the literature and were developed to simulate the site conditions in the laboratory. A modified Proctor test was adopted in the mix’s proportional process to optimize the aggregate’s percentage content of RCCP. The experimental series consisted of compression and split tensile performance tests to investigate the development of compaction performances at 28 days. The results showed that, where 10% of the cement was substituted by limestone, the RCC gives important flexural strength values compared to the quantity of the cement substitute. Qualitatively, the reduction in the strength of the concrete using the modified Proctor compaction method led to the weakness of the bond between the layers.

Sustainability and cost-effectiveness of steel and polypropylene fiber reinforced concrete pavement mixtures

By improving cracking performance, the use of discrete structural fibers allows to produce high performance concrete pavements with decreased thickness and without conventional reinforcement bars, so employment of them might be considered to enhance the sustainability of concrete pavements. However, the number of studies that examines the overall effectiveness of fibers in concrete pavement mixtures are limited, and this study was conducted to fill this gap in literature. In this scope, the efficiency of fibers (polypropylene and steel) in different concrete pavement mixtures and the effect of using them in varying amounts on the performance of concrete pavements were examined by doing an extensive experimental and numerical study. According to the experimental results, similar strength, stiffness, absorption, and porosity, but higher abrasion resistance and post-cracking performances were obtained for fiber reinforced concrete mixtures. In line with the post-cracking performances obtained for them, 2.2–19.8% and 15.9–27.5% reduction in required thickness values were found for polypropylene and steel fiber reinforced mixtures, respectively. Additionally, varying changes in pavement material costs (from 9.1% to 139.8% increase) and CO2 emissions (from 12.8% increase to 16.4% decrease) were obtained for FRC mixtures. Observations were found heavily dependent on the type and amount of fibers, as well as properties of concrete matrices. In the paper, several discussions and suggestions were provided to explain the reason and importance of the obtained results, and the authors believe that the paper will be beneficial for the following research studies and design works.

SUBSTITUSI LIMBAH PLASTIK “HDPE” SEBAGAI PASIR TERHADAP STABILITAS DAN KELELEHAN BETON ASPAL

In fact, plastic waste after being used becomes trash and makes the environment dirty. There are many ways to make waste useful by recycling, using it for decoration and so on. Much plastic waste is applied to concrete mixtures and pavement mixtures as a substitute for sand. The use of plastic scraps as sand is applied to the pavement layer of Hotmix to increase the value of road stability, flexibility and resistance to fatiq. Plastic wastehdpe will be used on the LASTON AC-WC pavement type. Pavement for class I roads, with pavement criteria referring to the Marshall Method. Sand quality from Lumajang and gravel from Pasuruan. The design with variations of 4.5%, 5%, 5.5%, 6% plastic is replaced by 0%, 5%, 10%, 15% and 20% for sand size Ø 2.36 mm. The parameters that are reviewed are the stability and melting as well as the optimum level of asphalt, then a conclusion is drawn whether they meet the existing hypothesis. This research is continuation of 2017 research. Follow up, will be carried out further research (year 2020), with variations of plastic waste and a review of other mechanical properties in terms of the effect of addition on flexible pavement behavior. Keywords: HDPE plastics, hotmix, laston, stability, flow and KAO

Development of framework for ranking pervious concrete pavement mixtures: application of multi-criteria decision-making methods

ABSTRACT The major objective of this study was to evaluate the performance characteristics of control and sand-modified pervious concrete (PC) mixtures through the development of a hybrid multi-criteria decision-making (MCDM) tool to rank the materials and recommend the most optimal performing products. A full-factorial experimentation was adopted to analyse porosity, density, permeability, and compressive strength for 36 PC mixtures. A hybrid MCDM tool involving analytical hierarchy process, Entropy, Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS), and VlseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR) methods was used to optimize the multi-response problem into a single output. Based on the results, the water-to-cement ratio may be restricted to a maximum of 0.30 and 0.33 for aggregates varying from 9.5 to 6.7 mm and 6.7 to 4.75 mm, respectively. Likewise, the cement-to-aggregate ratio may be restricted to a maximum of 1:3.75 and 1:4.25 for aggregate size in the range 9.5–6.7 mm and 6.7–4.75 mm, respectively. Further, the ranks for various PC mixtures obtained from TOPSIS and VIKOR were identical/ similar for about 80% of the mixtures. The proposed MCDM tools are envisioned to help the decision-makers in selecting the most optimum PC mix based on performance and site-specific requirements, a priori pavement design and construction.

New Approach to Determine Standard Deviation and Precision Estimates for ASTM D4867/D4867M and AASHTO T283

Abstract Moisture damage in asphalt pavements can be attributed to the incompatibility of the asphalt binder, aggregate, or the interaction of the asphalt binder and aggregate. Moisture damage can accelerate pavement distresses such as cracking and rutting. The most widely used test methods by state highway agencies are AASHTO T283-14, Standard Method of Test for Resistance of Compacted Asphalt Mixtures to Moisture-Induced Damage, and ASTM D4867/D4867M-09, Standard Test Method for Effect of Moisture on Asphalt Concrete Paving Mixtures. Some state highway agencies evaluate moisture resistance during production to ensure a quality asphalt mixture. Currently AASHTO T283-14 and ASTM D4867/D4867M-09 do not provide a method to calculate the standard deviation of the tensile strength ratio (TSR), nor does it provide precision estimates for the TSR. The objective of this paper is to show how one can calculate the variance (or standard deviation) of a variable when the value of interest (i.e., TSR) is calculated from two other random variables. The standard deviation of a random variable that is a quotient of two other variables can be calculated easily as long as the individual variables are random, independent, and the standard deviations are small relative to the mean. The novelty of this approach is in a statistics-based method for determining the standard deviation of the TSR based on using an approximation for the ratio variance using ASTM D4460-97, Standard Practice for Calculating Precision Limits Where Values Are Calculated from Other Test Methods. This new approach to calculate the standard deviation of the TSR will be used to develop a precision statement for AASHTO T283-14 and ASTM D4867/D4867M-09 following ASTM E691-19e1, Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method (Superseded).

Influence of Loading Pressure and Sample Preparation on Ionic Concentration and Resistivity of Pore Solution Expressed from Concrete Samples

AbstractPore solution expression is an established method to obtain samples of the liquid phase from cementitious systems. This experimental method applies pressure to a cementitious sample, forcing its liquid phase out of the pores. By collecting and studying the liquid phase in cementitious systems, it is possible to obtain information on its ionic concentrations. The ionic concentrations can be used for modeling calibrations and to estimate the resistivity of the pore solution. When the bulk resistivity of concrete is normalized by the pore solution resistivity, it is possible to determine the formation factor. The formation factor is related to the transport properties of the concrete and, as such, it can be used to estimate the rates of transport of ionic species within a concrete structure. The formation factor is currently being included in AASHTO PP84, Standard Practice for Developing Performance Engineered Concrete Pavement Mixtures, as an indicator of transport properties for quality control operations. Pore solution expression is included as one of the available procedures of AASHTO PP84-19 to determine the pore solution electrical resistivity. Previous studies on paste and mortar samples have demonstrated that increased loading pressure during the pore solution expression might impact the final ionic concentrations of the expressed solution. This study aims to verify if the pore solutions of concrete specimens are also influenced by the selected loading pressure and whether the potential consequent change in the measured ionic concentrations of the solution also has an impact on its resistivity. No appreciable trend in increased solubility was observed for the range of applied normal pressures between 600 and 985 MPa. Cyclic loading regimes increased the variability of alkali solubility. Sample preparation, in some cases, influenced the water content of the sample and induced unwanted alteration on the ionic concentrations of the mixtures under study.

Quantification of Calcium Oxychloride by Differential Scanning Calorimetry: Validation and Optimization of the Testing Procedure

Abstract The American Association of State Highway and Transportation Officials (AASHTO) T 365 standard, Standard Method of Test for Quantifying Calcium Oxychloride Formation Potential of Cementitious Pastes Exposed to Deicing Salts, describes a test methodology that uses low-temperature differential scanning calorimetry (LTDSC) to quantify the formation of calcium oxychloride in cementitious systems exposed to concentrated calcium chloride solutions. AASHTO T 365 is included in AASHTO PP 84, Standard Practice for Developing Performance Engineered Concrete Pavement Mixtures, as a performance indicator for mixtures at risk of calcium oxychloride formation. During the test, the sample temperature is first dropped to −90°C, looped through a brief thermal cycle, then slowly increased to a maximum of 50°C, at a constant heating rate of 0.25°C/minute (min), for a total testing time of approximately 11 hours. The objective of this work is to modify the test to reduce its duration to facilitate wide adoption among practitioners. It is found that by increasing the minimum conditioning temperature from −90°C to −5°C, as well as by increasing the heating rate from 0.25°C/min up to 1°C/min, the test duration can be reduced from approximately 10.7 hours to approximately 1.6 hours without any statistically significant difference in the numerical test results, although an offset of the melting peak and a change in its shape were observed. This change can provide valuable savings in terms of time and energy/gas consumption and make AASHTO T 365 more competitive with other available tests for the estimation of calcium oxychloride formation, such as thermogravimetric analysis (TGA). TGA and LTDSC are compared to each other in terms of mixture classification for susceptibility to calcium oxychloride formation. It is shown that the two tests show good agreement, with 85 % of cases (out of 30 tested) receiving the same classification.

Effect of Natrojarosite as Replacement to Portland Cement in Roller-Compacted Concrete Pavement Mixtures

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Employing a hybrid GA-ANN method for simulating fracture toughness of RCC mixture containing waste materials

The present study is conducted to investigate the efficiency of evolutionary algorithms such as genetic algorithm (GA)-evolved neural network in estimating fracture properties of roller compacted concrete pavement (RCCP) mixtures with different compositions. The effect of waste materials, including reclaimed asphalt pavement (RAP) and crumb rubber on fracture toughness in both pure mode I and pure mod II, were investigated using a real coded GA and an evolution with a back-propagation algorithm. Moreover, the geometry effect of SCB and 4 PB specimens on predicting fracture toughness was evaluated using GA. To evaluate the GA-based neural network's performance, the NSE criterion was applied for fitness function, a different approach for fitting in this area. Many researchers have studied the fracture behavior of RCC in diverse modes. Still, their studies have been restricted to the materials' fracture behavior, which has rarely come to a model. As pure mode II fracture toughness experiment is a complicated procedure with high uncertainties, the introduced model provides a powerful tool for predicting mode II fracture toughness via mix composition and pure mode I fracture toughness of RCC based on GA. The proposed model outperforms the traditional artificial neural network (ANN) models. The geometry effect survey on predicting fracture toughness shows that the 4 PB fracture model has been better fitted to observed data. Also, the MSE results show that prismatic specimens present relatively reliable results than SCB specimens.

Use of Coarse Recycled Concrete Aggregate in Ternary Blended Portland Cement Concrete

The purposes of this study were to (a) investigate concrete pavement mixtures with recycled concrete aggregates using ternary blended cementitious binders, (b) measure the fresh and hardened properties of the concrete mixtures, and (c) assess the durability of concrete implementing the use of recycled coarse aggregates with ternary binders. Mixtures had recycled concrete aggregates at varying replacement rates. The binders were combinations of Portland cement, Class C and F fly ashes, and ground granulated blast furnace slag. At 50% replacement of virgin aggregates, some specimens showed comparable mechanical performance to the control mix. Performance is heavily tied to quality of recycled aggregates. The combined use of fly ash and blast furnace slag showed improvements in results for drying shrinkage, freeze–thaw durability, resistivity, and alkali–silica reaction mitigation.

Effect of mix proportion on the structural and functional properties of pervious concrete paving mixtures

In recent years, pervious concrete pavement (PCP) is emerging as a novel pavement technology that is gaining a lot of attention amongst academicians due to its storm water runoff capabilities and mitigating urban heat island. This pavement technology consists of special types of concrete which has little amount of fines or no fines and interconnected voids. The different types of aggregate gradation, water-to-cement (w/c) and cement-to-aggregate, and compaction techniques with variations in efforts plays an important role in providing an optimum balance in the mixture designing of PCP mixtures. Therefore, the present study is an attempt to explore the possibility of variation of different aggregate gradation types with different proportion of w/c ratios for the production of PCP mixtures. Also, to study the effect of these mix properties on structural, functional as well as durable properties of PCP mixtures. Five aggregate gradation types and variability in w/c ratios were adopted in the present study viz. G1, G2, G3, G4 and G5, respectively. G1 and G2 consisted of larger-sized and well graded aggregates, while, G4 and G5 consisted of natural fines in proportion of 5% and 10%. Meanwhile, G3 consisted of binary blended single-sized aggregates: 30% of 10 mm and 70% of 4.75 mm. The above considered gradations were studied for porosity, density, permeability, compressive strength, flexural strength, and resistance to sulphate attack, at varied w/c ratios 0.30, 0.35, and 0.38, respectively. From an extensive laboratory investigation, it was observed that the G3 mix showed the best-balanced relation between all the afore-stated parameters, required for PCP mixtures. Hence, it can be recommended that the utilization of binary blended single-sized aggregates at a w/c ratio of 0.35 would provide an optimal solution keeping in mind the desired parameters of pervious concrete pavement mixtures are met.

Dynamic- and Static-Elastic Moduli and Strength Properties of Early-Age Portland Cement Concrete Pavement Mixtures

AbstractThis paper investigates the development of compressive strength (fc′), flexural strength (fr), and static elastic modulus (Ec) in relation to the dynamic modulus (Ed) for portland concrete ...

Drying Shrinkage and Cracking Tendency of Concrete Pavement Mixtures with Variable Packing Densities of Aggregates and Paste Contents

Excessive drying shrinkage, and associated cracking, can lead to serious durability problem in concrete pavements and bridges. In the course of this study, the magnitude of drying shrinkage and cracking potential was evaluated for several concrete pavement mixtures as a function of packing density of the aggregate and paste contents. The results indicated that both, the shrinkage and the cracking potential depend on the volume of voids between aggregate particles (packing density), paste content of concrete mixture, and the paste-aggregate void saturation ratio.

Strength and Porosity of Porous Concrete Pavement Containing Nano Black Rice Husk Ash

Rice husk ash (RHA) as replacement material in the conventional concrete mixture has been widely studying around the world. However, there is a lack of study on nanoparticle produced from black rice husk ash (BRHA) used as a replacement material in porous concrete pavement mixture. Therefore, this study aims to evaluate the performance of porous concrete pavement containing nano black rice husk ash in terms of compressive strength, porosity and its correlation. A nano BRHA dosage of 10, 20, 30 and 40% by weight of binder was used throughout the experiments. Four different grindings of BRHA were examined, and it was found that BRHA ground had a nanoparticle between 64 nm to 85 nm. There appears to be an optimum replacement of approximately 10% nano BRHA, during which time the compressive strength and porosity increase significantly.

Effects of Compaction Types and Compaction Efforts on Structural and Functional Properties of Pervious Concrete Paving Mixtures

Effects of Compaction Types and Compaction Efforts on Structural and Functional Properties of Pervious Concrete Paving Mixtures