Temperature influence on ordinary concrete modified with fly ashes from thermally conversed municipal sewage sludge strength parameters

Concrete is the most commonly used structural material, without which modern construction could not function. It is a material with a high potential to adapt to specific operating conditions. The use of this potential is made by its material modification. The aim of the performed investigations was the assessment of rational application possibilities of fly ashes from thermally conversed municipal sewage sludge as an alternative concrete admixture. A concrete mix was designed, based on the Portland cement CEM I 42.5R and containing various quantity of ash, amounting to 0–25% of cement mass. The samples were conditioned and heated in a furnace at the temperature of 300 ◦C, 500 ◦C, and 700 ◦C. Physical and chemical properties of the ashes as well as utility properties of the concrete, i.e., density, compressive strength after 28, 56, and 90 days of maturation, frost resistance, and compressive strength in high temperature were determined. The tests were performed at cubic samples with 10 cm edge. The replacement of a determined cement quantity by the fly ashes enables obtaining a concrete composite having good strength parameters. The concrete modified by the fly ashes constituting 20% of the cement mass achieved its average compressive strength after 28 days of maturation equal to 50.12 MPa, after 56 days 50.61 MPa and after 90 days 50.80 MPa. The temperature growth weakens the composite structure. The obtained results confirm the possibility of waste recycling in the form of fly ashes as a cement substitute in concrete manufacturing.This research was co-financed from EU funds, grant number POIR.04.04.00-00-0004/15

Wpływ rozdrobnionych odpadów szklanych na wybrane właściwości betonów sporządzonych z ich udziałem

Celem przeprowadzonych badań było poznanie wpływu dodania rozdrobnionych odpadów szklanych w trakcie sporządzania mieszanki betonowej betonu zwykłego na jego wybrane właściwości techniczne. W badanym zakresie mączka szklana wpłynęła nieznacznie na pogorszenie wytrzymałości na ściskanie, stłuczka szklana natomiast nie miała wpływu na wytrzymałość na ściskanie po 56 dniach dojrzewania. Dodatek mączki szklanej zwiększa wytrzymałość na zginanie, dodatek stłuczki szklanej utrzymuje porównywalną wytrzymałość na zginanie w stosunku do betonu referencyjnego. Uzyskane betony to betony mrozoodporne F150

New Achievements in High-Pressure Processing to Preserve Human Milk Bioactivity

High-pressure processing (HPP) is a non-thermal technology that is being increasingly applied in food industries worldwide. It was proposed that this method could be used as an alternative to holder pasteurization (HoP; 62.5°C, 30 min) in milk banks but its impact on the immunologic, enzymatic and hormonal components of human milk has not yet been evaluated in detail. The aim of our study was to compare the effects of HPP in variants: (1) 600 MPa, 10 min (2) 100 MPa, 10 min, interval 10 min, 600 MPa, 10 min (3) 200 MPa, 10 min, interval 10 min, 400 MPa, 10 min (4) 200 MPa, 10 min, interval 10 min, 600 MPa, 10 min in temperature range 19–21°C and HoP on the leptin, adiponectin, insulin, hepatocyte growth factor (HGF), lactoferrin and IgG contents in human milk. HoP was done at the Regional Human Milk Bank in Warsaw at the Holy Family Hospital on S90 Eco pasteurizer (Sterifeed, Medicare Colgate Ltd). Apparatus U4000/65 (Unipress Equipment, Poland) was used for pascalization. Milk samples were obtained from women during 2–6 weeks of lactation. Post-treatment culture showed no endogenous bacterial contamination in any tested option. Concentrations of selected components were determined using ELISA tests. The level of all analyzed components were significantly decreased by HoP: leptin 77.86%, adiponectin 32.79%, insulin 32.40%, HGF 88.72%, lactoferrin 60.31@.%, IgG 49.04%. All HPP variants caused an increase in leptin concentration, respectively (1) 81.79% (2) 90.01% (3) 86.12% (4) 47.96%. Retention of insulin after HPP was (1) 88.20% (2) 81.98% (3) 94.76% (4) 90.31% HGF (1) 36.15% (2) 38.81% 97.15% (3) 97.15% (4) 43.02%, lactoferrin (1) 55.78% (2) 57.63% (3) 78.77% (4) 64.75%. Moreover, HPP variant as 200 + 400 MPa preserved IgG (82.24%) better than HoP and resulted not statistically significant change of adiponectin level (38.55%) compare to raw milk. Our results showed that HPP leads to preservation of adipokines, growth factor, and lactoferrin, IgG much better or comparable with HoP

Assessment of Fly Ash from Thermal Treatment of Sewage Sludge According to the Applicable Standards

The restrictions on carbon dioxide emissions introduced by the European Union encourage experimental work on new generation materials containing smaller amounts of clinker. Currently, silica fly ash from the combustion of hard coal is widely used in cement and concrete technology in Europe and in Poland. Their wide application is mainly determined by their chemical and phase composition, especially pozzolanic activity , their high fineness, similar to cement. The aim of the research was to assess the properties of fly ash from thermal treatment of sewage sludge in terms of use in concrete technology in relation to EN 450-1, ASTM-C618-03 and ASTM C379-65T. The obtained test results confirm that the tested material has a different physicochemical composition and does not meet the requirements related to the use of ash in the production of concrete. In addition, the research showed the possibility of producing ordinary concrete, modified with fly ash from thermal treatment of sewage sludge. The average compressive strength for concrete containing 15% of ash from Cracow was set at 48.1 MPa and 49.2 MPa after 28 and 56 days of maturation, for ash from Warsaw at 42.0 MPa and 45.1 MPa, and for ash from Łódź at 36.2 MPa and 36.2 MPa. The determined concentrations of heavy metals are below the maximum values to be met when discharging waste water into the ground or water, the leaching limits required for accepting inert waste for disposal and for substances particularly harmful to the aquatic environment. On this basis, it was found that the migration of heavy metals from concretes with ash addition to the aquatic environment is insignificant and should not be a significant problem

Assessment of Fly Ash from Thermal Treatment of Sewage Sludge According to the Applicable Standards

The restrictions on carbon dioxide emissions introduced by the European Union encourage experimental work on new generation materials containing smaller amounts of clinker. Currently, silica fly ash from the combustion of hard coal is widely used in cement and concrete technology in Europe and in Poland. Their wide application is mainly determined by their chemical and phase composition, especially pozzolanic activity, their high fineness, similar to cement. The aim of the research was to assess the properties of fly ash from thermal treatment of sewage sludge in terms of use in concrete technology in relation to EN 450-1, ASTM-C618-03 and ASTM C379-65T. The obtained test results confirm that the tested material has a different physicochemical composition and does not meet the requirements related to the use of ash in the production of concrete. In addition, the research showed the possibility of producing ordinary concrete, modified with fly ash from thermal treatment of sewage sludge. The average compressive strength for concrete containing 15% of ash from Cracow was set at 48.1 MPa and 49.2 MPa after 28 and 56 days of maturation, for ash from Warsaw at 42.0 MPa and 45.1 MPa, and for ash from Łódź at 36.2 MPa and 36.2 MPa. The determined concentrations of heavy metals are below the maximum values to be met when discharging waste water into the ground or water, the leaching limits required for accepting inert waste for disposal and for substances particularly harmful to the aquatic environment. On this basis, it was found that the migration of heavy metals from concretes with ash addition to the aquatic environment is insignificant and should not be a significant problem

Computational Fluid Dynamics in Patient-Specific Models of Normal and Chiari I Geometries

Chiari I malformation characterizes by cerebellar tonsils descending below foramen magnum, leading to obstruction of subarachnoid space (SAS) that alters the cerebrospinal fluid (CSF) flow. The condition leads to diverse symptoms in patients and is in some cases accompanied by a syrinx in the spinal cord. In order to improve the understanding of effects of SAS geometry on the CSF flow characteristics, numerical simulations of the CSF flow were conducted on a a series of personalized models of Chiari I patients, healthy volunteers and post-operative patients. The models were generated with the help of VMTK, which is a software tool for reconstruction of anatomical structures based on segmentation of medical images. To simulate the CSF flow, we applied the Navier Stokes equations for incompressible Newtonian fluid, which were solved numerically by applying the Finite Element Method (FEM) to the Incremental Pressure Correction Scheme (IPCS). The simulations were conducted by means of a pre-provided code for computational fluid dynamics (CFD) based on the FEniCS software library. To assess the validity of our results, the computed velocities were compared with MRI-measurements of the studied patients. If the computations were significantly different from the velocity measurements, the inflow and outflow conditions were changed accordingly and new simulations were conducted. Chiari I models have shown more evident flow complexities, greater peak velocities, higher flux-values and larger magnitude of bidirectional flow compared to models of healthy volunteers. We observed that to achieve more realistic results in future simulations, setting pressure and velocity conditions based on MRI measurements is recommended

ANALYSIS OF VARIANTS THERMOMODERNIZATION OF A DWELLING HOUSE FROM A POINT OF VIEW OF OPTIMAL ENERGETIC DEMANDS

Energy is the basic element and building block of the world – it is pervasive. In comparison to other European countries, Poland allots still too much quantites of energy for heating of buildings which mostly had been built without concern for ecological and economical aspect of heat consumption. Therefore more and more investors decide to thermomodernize their buildings because of the energy savings and increase of the comfort of use of the building. The paper presents the analysis of thermomodernisation variants of an existing dwelling house from the point of view of the optimal adjustment for energetic supply. There was defined the optimal thickness of insulation for a vertical baffle and roof for various configurations of layers. The calculations of cost-effectiveness were carried out for the investment with the use of the NPV index for various thicknesses of the insulation, including the case without insulatio

Fly ash from thermal transformation of sewage sludge as an alternative additive to concrete resistant to environmental influences

Concrete is currently the most widely used man-made composite material and second only to water in the entire range of materials used. It is a material with a high potential to adapt to specific operating conditions and can be made from local raw materials (aggregate, cement, water, and mineral additives), which can be selected to minimize the carbon footprint. The use of fly ash from the thermal conversion of sewage sludge in concrete is in accord with the advice on waste management proposed in the European Union. This paper presents the results of research on the effect of the partial replacement of Portland cement with this material on the strength parameters, frost resistance, and carbonation of concrete compared to reference concrete and to concrete containing a conventional additive – siliceous fly ash. In addition, the potential environmental impact of the use of sewage sludge ash was investigated by determining the leachability of heavy metals. Concrete mixtures of C20/25 ordinary concrete, based on CEM I 42.5R Portland cement, with varying ash contents comprising 0–20% of the cement mass, were produced for the experimental work. The obtained test results confirmed the possibility of producing plain concrete modified with fly ash from the thermal treatment of sewage sludge and the concrete’s compliance with the environmental requirements relating to the leaching of heavy metals

RESEARCH OF PROPERTIES OF CONCRETE WITH THE USE OF FLY ASH

Taking care of the environment in accordance with the principles of sustainable development introduces the possibility and the need for waste recycling. The greatest potential for reuse of waste has the construction industry – building materials industry. The article presents the results of selected properties (consistency, water absorption, water resistance and compressive strength after 28 days of ripening) of ordinary concretes and concretes containing in its composition the maximum amount of fly ash. Studies have demonstrated the usefulness of fly ash as a substrate for the production of concrete components

EFFECT OF FLY ASH FROM THE INCINERATION OF SEWAGE SLUDGE ON THE STRENGTH AND FROST RESISTANCE OF FINE-GRAINED CONCRETE

According to the data of Polish Central Statistical Office (GUS), 526,000 Mg. of sludge solids were produced in 2010 in Poland. Moreover, it is expected in the National Program of Municipal Wastes Treatment that the quantity of sludge in 2015 will grow till 662000 Mg. of sludge solids. It is the effect of dynamic development of the sewerage system in Poland. One of the possibilities of the recycling such ashes is their application in the production of building materials, such as grained concrete. Such solution gives ecological and economical advantages. The paper presents the results of investigations of properties (consistency, compressive strength and tensile strength after 28 and 56 days of curing, frost) of grained concretes as well as the concretes containing various quantity of fly-ashes produced in the thermal recycling of municipal sludge. Concrete with addition of fly-ashes was produced in four versions. In the two ones, the quantity of ashes equal 15% and 20% of the cement mass was added and in the another two versions 15% and 20% mass of the cement was replaced by the ashes. After the investigations it was stated that the applied admixture improves the properties of the grained concrete, hence, reduces the costs of its production