Coupling machine learning with thermodynamic modelling to develop a composition-property model for alkali-activated materials

Alkali-activation is one of the most promising routes for utilisation of versatile aluminosilicate resources. However, the variations of chemical compositions in these resources have increased the challenge of designing alkali-activated materials (AAMs) with multiple sources, posing the demand for establishing composition-property correlations that can represent a wide range of AAMs. This study proposes a data-driven approach to develop such composition-property correlations combining machine learning with global sensitivity analysis and thermodynamic modelling. The strength performance of alkali-activated concretes was investigated for a benchmark study (196 data inputs). The impact of the five key chemical compositions, CaO–SiO2–Al2O3–MgO–Na2O, has been assessed. The results show that despite the use of different aluminosilicate precursors, there appear to be coherent connections between bulk binder chemical compositions, phase assemblages, and the performance of AAMs. The composition-property correlations established via machine learning can be used to facilitate the on-demand design of AAMs utilising varying aluminosilicate resources.</p

Study on the Effect of Micro-Incinerated Rice Husk Ash (MIRHA) and Fly Ash (FA) in Geopolymer Cement

The objective of this research is to study Fly Ash (FA) and Micro Incinerated Rice Husk Ash (MIRHA) as a cement binder replacement for Ordinary Portland cement (OPC). Both Fly Ash and MIRHA are categorized as pozzolonic materials in which when combined with calcium hydroxide, will exhibits cementitious properties. This supplementary cementitious material is proven to be effective to meet most of the requirement of durable concrete as well as cement. In the modern oil and gas industry, the utilization of both these materials as cement blend is gaining the attention of many. When compared to OPC, its application is generally cheaper, reduce the environmental effects especially on carbon dioxide (CO2) emission and improve the ordinary cement blend. Both materials are easily obtained from waste or by-products generated through industrial and agricultural activities. MIRHA was mixed with FA by the ratio of 1:1 and 3:7 without any addition of OPC, fine aggregate or coarse aggregates. The effect of curing time for 3, 7 and 14 days, water to binder ratio (w/b), water ratio and different mixture composition were studied through the observation of the final compressive strength result of the samples. The project is solely based on experimental analysis. The laboratory works will be carried out in Universiti Teknologi PETRONAS (UTP) Petroleum Engineering and Civil Engineering laboratories. The experiments start from the incineration process to retrieve MIRHA and Rice Husk Ash (RHA), sieving, mixing, blending of the raw material and finally compressive strength test. The results indicate that the compressive strength development was the highest for batch A3 at 5 MPa by the 14th day, with 30wt.% MIRHA to 70wt.% FA, 10% water and w/b ratio of 0.95 in which the ratio of MIRHA and water was the lowest. Though the targeted compressive strength was no achieved, it was identified that the reduced amount of MIRHA and water appear to be the main contributor to the increasing compressive strength of geopolymer binder

Effect Of Aggregate Propertıes On The Mechanıcal And Absorptıon Characterıstıcs Of Geopolymer Mortar

Üretiminde önemli çevresel sorunlara neden olan Portland çimentosunun imalatı için çeşitli doğal kaynaklar tüketilmektedir. Jeopolimerizasyon adı verilen yeni bir teknolojik süreç bu konuda yenilikçi bir çözüm getirmektedir. Jeopolimerler karbon emisyonu potansiyelini düşürmenin yanı sıra, uçucu kül, öğütülmüş yüksek fırın cürufu, metakaolin, vb. gibi birçok endüstriyel atık ürünü veya doğal puzolan ile sentezlenebilir. Bu çalışmada, uçucu kül esaslı jeopolimer harcın agrega özellikleri ile bazı mühendislik özellikleri arasındaki ilişkiyi ortaya koymak amacıyla deneysel bir çalışma yürütülmüştür. Bu amaç doğrultusunda, agrega olarak iki tür kum ve dört farklı gradasyon kullanılmıştır. Jeopolimer bağlayıcı, alkalin sıvılar ve uçucu kül karışımından oluşmaktadır. Kırma kireç taşı, karışık kum ve doğal kum için sırasıyla basınç dayanımı değerleri 47.83-40.25 MPa, 44.93-38.09 MPa, ve, 39.37-28.25 MPa aralığındadır. Ayrıca, su emme ve kılcal su emme deneyleri ile jeopolimer harçların geçirimlilikleri değerlendirilmiştir. Elde edilen test sonuçlarına göre uçucu kül esaslı jeopolimer harcın su emme kapasitesinin karışık agregalı olanlarda (%50 kırma kireç taşı ve %50 doğal kum), tek tip agregalı olanlara kıyasla iyileştiği gözlenmiştir

Rehabilitation of Sewer Pipes and Related Infrastructure with Geopolymer and Alkali-activated mortar

The concrete sewer pipe network, comprising approximately 122,000 km across Australia, is crucial for ensuring the livability and productivity of cities and communities. It was designed with an intended service life of around 100 years. However, these sewer assets face deterioration due to various factors, including microbial-induced concrete corrosion (MICC), which is the most aggressive threat. The MICC involves complex chemical and biological reactions, leading to the degradation of sewer assets in a short period. To mitigate MICC impact, several strategies focus on reducing hydrogen sulphide (H2S) through chemical dosing and surface protective coatings. However, these approaches pose long-term operational and financial challenges. Surface protective linings, particularly alkali-activated binders (AAB) like geopolymer, offer a promising alternative. Despite their promising qualities, these materials have not been utilised as protective linings in sewer asset applications for a few reasons. For example, there is a lack of corrosion resistance performance data and guidelines for their application and selection, especially in actual sewer environments. This study addresses these challenges by developing a framework to predict the service life and select criteria for AAB mortar under live sewer conditions using four commercially available geopolymer mortars (OGPm) and one calcium aluminate cement mortar (CACm). The results indicated three stages of corrosion steps, with CACm outperforming OGPm due to its composition, ANC, porosity, and UCS. The study presents service life prediction models for AAB mortar, incorporating sewer environment conditions, mortar properties, and time. This research marks the first instance of developing a service life prediction model considering real-world field applications, contributing valuable insights into the selection of protective lining materials for sewer asset rehabilitation