An Experiment and Study of M30 Grade of Concrete by Partially Replacing Fine Aggregate with Marble Dust Powder and Phosphogypsum in Rigid Pavement

The Project is to study about M30 grade of concrete by adding waste materials. Marble dust powder and phosphogypsum which is easily available marble which are standard among the most imperative materials, utilized as a part of the development business. Marble dust is a waste material from the construction site is mixed with concrete as a replacement material. Marble dust powder is acquired from sawing and moulding of marble rock. Phosphogypsum is produced as an outgrowth of the production of fertilizer from phosphate rock. There is a high gypsum content and gypsum is a widely used material in constructions. It is weakly radioactive in nature because it is a by-product of phosphate fertilizers. In the M30 grade of concrete fine aggregate is partially replaced by marble dust powder and phosphosgypsum in some proportions. The fine aggregate is replaced by 10%, 20% and 30% in which marble dust powder and phosphogypsum and are added in an equal proportion. Keywords: Marble dust powder, phosphogypsum, grade of concrete, rigid pavement, green concrete.

Experimental study on mechanical behavior of orthotropic steel deck with adhesively bonded rigid pavement

The steel deck with rigid pavement has a lower risk of fatigue failure owing to the enhanced local rigidity. A reliable connection of steel plate and pavement and a convenient construction are critical concerns for this deck type. To seek a new application meeting the aforementioned requirements, this paper proposed a steel deck with adhesively bonded rigid pavement cast by non-reinforced ultra-high performance concrete (UHPC). To study the constructability and flexural properties of this deck type in a bridge deck system, four specimens including two with adhesively bonded connection and two reference ones with shear stud connection were fabricated and experimentally investigated by positive and negative bending tests. In addition, a simplified pretreatment of steel substrate was conducted before the application of epoxy resin to simulate the low quality of on-site construction. Experimental results indicate that the shear strength of the bonding connection with simplified steel pretreatment could decrease to half of that with strict preparation. Bending tests demonstrate that the adhesive bonding provides a more rigid connection between steel and concrete than shear studs did. The bonding failure load was 1.5 times the U-rib yielding load, indicating a high positive bending-carrying capacity of the deck. The adhesive provides better crack resistance than shear studs in negative bending. From a perspective on the bending behavior in the deck system, the adhesive bonding was reliable to obtain high bending capacities to resist actual vehicle loads. Besides, the non-uniform shrinkage of non-reinforced UHPC pavement can cause a 30% reduction of cracking strength.

EXAMINATION OF THE QUALITY OF NANOMATERIALS IN THE DEVELOPMENT AND APPLICATION OF CIRCULATING RESOURCES IN CONSTRUCTION

the advantage of the equality indicator is the relative simplicity of definition and the possibility of periodic moni-toring. According to the equality indicator, it is possible to assign repairs and predict the service life, assess the condition of the road surface. Experimental studies have proved that there is a connection between the evenness of the coating and the strength of the pavement, which opens up the possibility of determining the structural strength of non-rigid pavement, which provides a given evenness of the coating for the last year of operation be-fore major repairs. The question of assessing the impact of the unevenness of the road surface on the processes of development and accumulation of deformations, changes in the evenness of the coating during operation remain largely open. This is due to the multifactorial nature of the problem of predicting the equality of coverage, so it is advisable to use approaches based on direct measurement methods. Most of the existing models of interaction of a pneumatic or rigid wheel with a coating are designed for problems of pavement mechanics or car theory, therefore they cannot be unambiguously applied to determine the value of the dynamism coefficient. A significant disad-vantage of these solutions is insufficient consideration of the deformative properties (modulus of elasticity) of the pavement.

Statistical Study Based on the Kriging Method and Geographic Mapping in Rigid Pavement Defects in Southern Chile

ASTM D6433 is used to assess the need for maintenance of pavement sections. Although the Pavement Condition Index (PCI) factor calculation method provides reliable values, this method analyzes sections and defects individually and indicates current maintenance needs, but it cannot be used to predict the occurrence of new defects. Therefore, it is necessary to complement this method by considering variables that influence the occurrence of faults, among which are the geospatial distribution and the specific characteristics of the slabs. This research focuses on the identification of multiple types of disturbances that exist in Portland Cement Pavements (PCC), located in a high traffic area in the city of Valdivia (Chile). A spatial geostatistical relationship is established through visual inspection using geographical maps, as well as distribution, using the kriging method. This technique makes use of variograms that allow quantifying the parameters used in this study, thus expressing the spatial autocorrelation of the faults analyzed. From the results obtained by spatial geostatistics and kriging, it is possible to generate a data correlation for the distribution and characteristics of the streets considered. In addition, a co-kriging method is established instead of an ordinary kriging method. The relationship between observed and predicted values improved from 0.3327 to 0.5770. The width of the slabs, as well as some streets, is shown in our analysis to be unimportant. For better model accuracy, the number of covariates associated with the type of vehicle traffic, the age and shape of the slabs, and the construction techniques used for the pavement needs to increase.

Effect of Using Ground Granulated Blast Furnace Slag in Rigid Pavement Overlays

Cement is replaced with Ground Granulated Blast Furnace Slag (GGBS), to produce a cost effective concrete and to gain effective compressive strength. It is produced in iron manufacturing industries. It has pozzolanic properties and has particle size less than 90μ. In this experimental study, cubes of size 150×150×150 mm and cylinders of 150 mm dia and 300 mm height were casted byreplacing GGBS from dosage of 8% up to 65% for curing period of 7days, 14days, 28days and 56days for M 40 grade concrete. Also, Alccofines were added in addition in varying percentage of 3%, 6%, 9% and 12% in order to gain high early strength and increase the workability. Hyper-Plasticizers were also added in order to reduce the water-content of the concrete. The results of GGBSCC were compared with that of normal concrete results.

The use of olive waste for development sustainable rigid pavement concrete material

Recycle and reuse of agriculture and industrial wastes becomes a big chalenge in different parts of the world. The success in the waste recycle could lead to conserve the environment, reduce the use of cement, and improve health environment. This paper presents the potential use of fly ash from olive oil waste in Jordan to improve concrete material which could be used as a sustainable material for rigid pavement and building construction material. Olive oil ash was collected from olive oil mill and replace cement in producing concrete material. The range of cement replacement was 0% to 12.5% with increment 2.5%. The results indicate that olive oil reduces the workability of concrete material. The reduction of the slump of concrete increases with increasing olive ash content. Strength and durability of concrete improved and increased with increasing olive ash content in concrete up to 7.5 percent then the strength reduced. The results in this study show that the use of 7.5% was the optimum replacement of cement. This percent could produce concrete with higher strength and higher durability in comparison with the control concrete mix. Olive waste ash enhances both strength and durability because it reduces the effective water-cement ratio in concrete mix and filling the pore and void structure in concrete material. The benefits of this study could reduce the cost of concrete and recycle waste material and enhance concrete properties.

Investigating Alternates to Flexural Beams for Airport Concrete Strength Compliance

Concrete for airport rigid pavement construction is generally specified to achieve a minimum characteristic flexural strength of 4.5 MPa and acceptance testing during construction aims to verify this key design assumption. The large flexural beam specimens are cumbersome and the testing is expensive. Consequently, industry desires a more convenient test and a laboratory-based conversion to an estimated flexural strength for acceptance testing during production. This research developed and trialed a protocol for the conversion of indirect tensile strength and compressive strength to estimate the flexural strength. The laboratory correlation was encouraging. However, when trialed on a real construction project, the conversions significantly underestimated the measured flexural strength and the risk of rejecting compliant batches of concrete was significantly higher. Further research is required to understand why the reliable conversions developed in the laboratory failed in the field. This may be related to the effect of ambient temperature on 28 day flexural strength, despite the constant curing condition.

Validation Of A New Method For Determining The Remaining Service Life Of Rigid Pavements

About a half of the Austrian highways are rigid pavement constructions, and increasingly more money has to be invested in their renovation and redevelopment. However, there are different approaches for the evaluation of the condition assessment of concrete pavements. The aim of the research presented in this paper is a concept for assessing the condition of a road section in rigid pavement. This consists of a structural and a visual assessment scheme for selecting appropriate maintenance actions. For the verification of this new method of assessment of the structural condition of concrete pavements, several field tests were examined. Furthermore, a case study was carried out to examine the level of influence of several input parameter. This analysis shows that the influence of the layer thickness is very high, while the influence of the modulus of elasticity of the existing concrete is significant lower. The FWD measurements were carried out radial (instead of linear) for the first time. The results show possible inhomogeneities in the subgrade or in the bedding, which would not be recognized by the standard linear measurements. With the results from the already mentioned measurements, the remaining service life of the test tracks could be calculated.