Performance analysis of a Cold Asphalt Concrete Binder Course Containing High Calcium Fly Ash Utilizing Waste Material

It has been established that cold bituminous emulsion mixtures (CBEMs) have a comparatively low initial strength in comparison to hot mix asphalt (HMA), however its superior performance with regard to carbon emissions, is a significant driver regarding its manufacture. In this research, high calcium fly ash (HCFA) together with a fluid catalytic cracking catalyst (FCC) - a rich silica-alumina waste material - have been incorporated to develop a new cold asphalt concrete binder course (CACB) bituminous emulsion mixture. HCFA was used as a substitute for traditional limestone filler while FCC was the additive used to activate the HCFA. The mixtures’ performance was assessed using the indirect tensile stiffness modulus test (ITSM), assessment of resistance against permanent deformation, temperature and water sensitivity tests. Surface morphology was tested using a scanning electron microscopy (SEM). A considerable improvement was identified by the ITSM test in addition to a substantial enhancement in rutting resistance, temperature susceptibility and water sensitivity. It was also established that the addition of FCC to CACB mixtures was found to improve early strength as well as long-term strength, rutting resistance, temperature sensitivity and durability

Laboratory Studies to Examine the Properties of a Novel Cold-Asphalt Concrete Binder Course Mixture Containing Binary Blended Cementitious Filler (BBCF)

Conventional hot asphalt mixtures have an impact on global warming and CO2 emissions contributing to debates on environmental issues which have been raised in recent years. As an alternative, cold emulsion asphalt mixtures (CBEMs) provide considerable benefits such as eco-friendliness, energy efficiency and cost effectiveness connected with safety. However, their weak early strength along with the need for longer curing times (usually 2-24 months) and higher moisture susceptibility compared to hot asphalt mixtures, have been cited as obstacles to their wider application. That said, the incorporation of waste materials in CBEM mixtures enhances sustainability by decreasing the amount of industrial waste materials needed and conserving natural resources. A new binary blended cement filler (BBCF) material generated from high calcium fly ash (HCFA) and fluid catalytic cracking catalyst (FC3R) was found to be very effective in providing microstructural integrity with a novel fast-curing cold asphalt concrete for the binder course (CACB) mixture. Laboratory performance tests included the stiffness modulus test by indirect tension to cylindrical samples, wheel-tracking tests and water sensitivity. Regarding environmental issues, a toxicity characteristic leaching procedure (TCLP) test was performed to analyse the leachate from various specimens comprising concentrations of heavy metal. The findings of these tests have demonstrated that CACB performs extremely well compared to traditional hot mixtures. The stiffness modulus of the BBCF treated mixture – 3730 MPa after 3 days – is higher than the traditional hot mixture (100/150 pen). In addition, the BBCF treated mixture offered a superior performance regarding rutting resistance, fatigue resistance and water susceptibility as well as revealing a considerably lower thermal sensitivity. More significantly, the BBCF treated mixture was found comparable to the traditional asphalt concrete binder course after a very short curing time (1 day). Finally, the concentration of heavy metals in the specimens incorporating the BBCF was observed to be less than the regulatory levels determined for hazardous materials and so requirements were satisfied. Consequently, this BBCF treated mixture has significant potential with reference to its application as a binder course in asphalt pavement

The effect of using fluid catalytic cracking catalyst residue (FC3R) "as a cement replacement in soft soil stabilisation"

Construction sector suffer from many problems due to presence of the soft soil in many worlds' parts and to solve these problem the soft soil should be stabilised by either mechanically or chemically; the mechanical ways can be achieved by replacing with stronger materials or using special machines to increase the soil stability result which considered high cost, researchers try to find another method with alternative materials like cement, lime and pozzolanic materials to qualify the soft soil on the civil engineering project. The aim of this study is to evaluate the soft soil properties that cured with 9% binders of various mixtures of binary blended produced from Ordinary Portland cement (OPC) and Fluid catalytic cracking catalyst residue (FC3R), which is a by-produced material from petroleum sector. Geotechnical tests like (compaction, un-confined compressive strength (UCS) test and Scanning electron microscopy (SEM)) were used to investigate the optimum binary mixture. Results show that the use of FC3R as a cement replacement developed the strength of soft soil after 28 days result in a higher strength comparison to using OPC alone in soil stabilisation. SEM proved presence of OPC hydration products during different curing ages. © IAEME Publication

Evaluation of the properties of modified local asphalt binder by using styrene butadiene rubber (SBR) or low-density polyethylene (LDPE)

The influence of styrene butadiene rubber (SBR) or low-density polyethylene (LDPE) polymers on the characteristics of local asphalt binder was analyzed to characterize the rheological properties. The results indicated that the SBR or LDPE increased the softening point. The softening point was enhanced by around 35% when 9% of SBR was used in comparison to the unmodified asphalt, while there was a 15% increment when LDPE was used. The results also indicated that the SBR or LDPE decreased the penetration rate. The penetration decreases by around 36% when 9% of SBR is used compared to the neat asphalt, while a significant increment was 89% when 9% of LDPE is used. Additionally, when 9% SBR was employed, the ductility of the asphalt binder rose by roughly 73%, but 64% less ductility was seen when 9% LDPE was utilized. Finally, the addition of the additive has improved the penetration index, thus reducing the temperature sensitivity. Due to said above, SBR and LDPE are practical and promising modifiers that will be useful in enhancing the performance of the asphalt binder straightforwardly and efficiently

Prospect and barrier of 3D concrete: a systematic review

This paper aims to explore the current state of the art and potential of 3D concrete printing and its use in large-scale applications. The study analysed 373 academic research, all of which were obtained from the Scopus database. The review conducted on some crucial issues on development of 3D concrete that included materials and their desirable properties, printer nozzle developments, reinforcement in printing, geopolymers as printing materials, and the use of coarse graded aggregates. This study provides researchers and institutions with an in-depth insight into 3D concrete printing and research trends worldwide and assesses the future of 3D concrete printing in large-scale applications. The requirement of more research on the mechanics of 3D printers, standardising a printer nozzle, the automation of reinforcing processes, and use of coarse graded aggregate for large-scale structural application were identified in this review. It also shows how 3D concrete printing has evolved and changed over time and gives an insight into the future of 3D concrete printing—making this scientometric review a framework for future studies

Impact of New Method for Laying Separate Sewer System on Pavement Layers

The method of installing underground infrastructure has a significant influence on road resistance and performance under live loads such as traffic. This research presents a new method for laying separate sewer systems by using one trench to sit both sanitary pipe and storm pipe and considers the effects of this approach on the pavement strength. Experimental tests have been conducted in the laboratory using a trench 2.5x0.45x1 metre to install two pipes one over the other (sanitary pipe in the bottom and storm pipe on top). Two cases have tested, the first case using 5 cm surface layer of cold mix asphalt while the second is using soil. A series of loads were applied to test the behaviour of this new system and its effects on the pavement surface layer and the buried pipe. The comparison between the rut print of the live load on the soil layer and the pavement layer was conducted. Results demonstrated that using the cold mix asphalt is still insufficient to provide enough safety to protect buried pipe as a reason of needing to relatively long time to acquire high stiffness. Therefore, minimum cover depth to protect pipelines still required

High performance cold asphalt concrete mixture for binder course using alkali-activated binary blended cementitious filler

A slow rate of curing and the long time necessary to achieve full strength has led cold asphalt mixes (CAM) to be considered poorer in comparison to hot mix asphalt over the last decades. This piece of research aimed to develop a new fast-curing and environmentally friendly cold asphalt concrete for binder courses mixture (CACB). It has the same gradation as that of traditional hot asphalt concrete mixtures but incorporates a binary blended cementitious filler (BBCF) containing waste, high calcium fly ash (HCFA) and fluid catalytic cracking catalyst residue (FC3R) activated by a waste alkaline NaOH solution. The research concludes that incorporating an alkali activated binary blended cementitious filler (ABBCF) with CACB significantly improves the mechanical properties and water susceptibility. In addition, the high performance ABBCF mixture has a substantial lower thermal sensitivity than traditional hot asphalt concrete binder course mixtures. SEM analysis revealed that the main crystallisation had taken place at an early stage of the new ABBCF. More significantly, the new CACB mixture has a comparable stiffness modulus with the traditional asphalt concrete binder course after a very short curing time (less than one day)

Shear performance of beam-column joints subjected to high loading rates

High loading rates may produce in structural frames due to some actions, such as explosions or debris impact. The response of structural members to such abnormal loadings should be investigated to provide comprehensive knowledge of their capability to resist impulsive forces. The beam-column joint is considered one of the most important structural components that significantly control the robustness and integrity of a structural frame. Hence, in the current study, eight full-scale specimens of two types of beam-column joints were tested under dynamic impact load to study their response to high rate load. These two types of joints were fin-plate and single angle-cleat joints. The tests were carried out using a drop hammer to apply an impact load on the specimens from different heights with different preloading conditions. The single angle-cleat joints exhibited a better response to dynamic loads with different impact height and preloading conditions than fin-plate joints in terms of resistance and ductility. Bolt shear failure was the dominant failure mode of the two types of the joints selected

The Development of a New Cementitious Material Produced from Cement and GGBS

The aim of this research is to study the effect of using Ground Granulated Blast Furnace Slag (GGBS) as a partial replacement to Ordinary Portland Cement (OPC) and produce a more environmentally friendly cementitious material with comparable compressive strength to OPC. Six mixes were prepared with different percentages of GGBS replacement 0%, 10%, 20%, 30%, 40% and 50% of the weight of OPC. The compressive strength with ages of 7 and 28 days was used for evaluating the performance of the tested specimens in comparison to the control mix with (0% GGBS). The results demonstrated that the compressive strength at the age of 7 days for the mixes with 10% and 20% GGBS were higher than the control mix by 2% and 4%, respectively. However, the addition of 30%, 40% and 50% caused a reduction in the compressive strength relative to control mix by 3.6%, 12.7% and 15.6%, respectively. Interestingly, all the mixes containing GGBS provided higher compressive strength in comparison to the control mix at the age of 28 days. This means that increasing the period of curing for mixes containing GGBS can improve the compressive strength. At 50%, GGBS substitution the strength of mortar was better than the strength of control mix at 28 days. In this study, the optimum replacement of OPC by GGBS was considered to be 50%. Such replacement will contribute to reduce the CO2 emissions (carbon footprint) and at the same time provide better compressive strength at suitable curing times