The brick walls of ancient buildings have got a lot of tiny and closely connected pores inside, so they can soak up water really well. This can easily cause problems like getting powdery and having efflorescence. To stop water from spoiling the grey bricks, this paper focuses on the brick walls of historical buildings in Kaifeng City. Based on our investigation, we study the distribution features of the problems. This paper tells about using the method of negative pressure infiltration to change the grey bricks. We measure all kinds of basic indicators and analyze how different ratios of modifiers affect the water properties and dry-wet cycle tests of the grey bricks. We look at the changes in the inside shape through SEM to show how it changes the grey bricks of ancient buildings. Second, we improve the wet walls by using a way that combines blocking and drainage. The main things we studied and the conclusions are like this: We use sodium methyl silicate and acrylamide polymer as modifiers to soak the historical grey bricks under negative pressure. We figure out the best ratio through orthogonal experiments. We analyze things like the water vapor permeability, how long it takes for a water drop to go through, the compressive strength, the water absorption rate, and the height of water absorption of the modified bricks. The results show that the crosslinking agent and acrylamide monomer have a big influence on how high the capillary water goes up in the modified bricks. The air permeability of the modified grey bricks with acrylamide polymer goes down a bit, but it's still okay. The surface of the modified grey bricks is very hydrophobic and there are fewer pores inside. The mechanical properties of the modified grey bricks get better in different degrees. The water absorption rate and the height of capillary water absorption go down. The modified grey bricks can really cut down the erosion of water on the wall when used in real life. They can reduce salt crystallization and efflorescence caused by rising water, and so make the brick walls of historical buildings last longer. This is super important for protecting historical buildings in Kaifeng City and taking care of other similar structures. Also, by using a way that combines blocking and drainage, and putting polymer infiltration reinforcement and the ventilation of the moisture drainage pipe together, the results show that this combination can really lower the height that capillary water goes up in the brick wall. So we get a way to control how wet the wall is.

Local ecological materials in construction represent a fundamental step toward creating living environments that combine environmental sustainability, energy efficiency, and occupant comfort. It is part of an organizational context that encourages the adoption of these methods and processes. This study aims to improve the use of locally available materials, particularly soil and agricultural residues, in the Errachidia region (southeastern Morocco). In particular, date palm waste fiber, a widely available agrarian by-product, was incorporated into the soil to develop six different types of stabilized earth bricks with fiber contents of 0 %, 1 %, 2 %, 3 %, 4 %, and 5 %. The aim was to evaluate their thermophysical, mechanical, and capillary water absorption properties. Thermal properties were determined using the highly insulated house method (PHYWE), a specific methodology for assessing thermal properties in a controlled, highly insulated environment. In addition, mechanical measurements were carried out to assess compressive and flexural strength. The results obtained showed that the addition of date palm waste fibers to brick based on soil improves the thermal resistance of the bricks. Flexural and compressive strength increased up to 3 % of fiber content, while a reduction was observed above this value. The 3 % fiber content is optimal for the stabilization of brick based on soil. Then, the increase of fiber content in bricks resulted in an increase in water absorption with a decrease in the density of the bricks. Physical and chemical characterization (XRD, FTIR, SEM, and EDX) of the soil and date palm waste fibers was carried out with geotechnical soil tests. The results obtained showed that the soil studied satisfies the minimum requirements for the production of bricks stabilized by fibers. These bricks can be considered an alternative to conventional bricks in ecological construction.

Recycled coarse aggregate is processed through the second crushing, which causes some internal damage, resulting in its physical indicators being far worse than natural coarse aggregate; its durability is relatively poor, and in the northern region, the soil contains a large number of acidic salt ions from the erosion of concrete, resulting in a decline in its durability. In this test, concrete was made from the single and composite immersion of recycled coarse aggregate using 5% water glass and 8% silane solution and subjected to a rapid freeze-thaw test in water, 3.5% NaCl solution, and 5% Na2SO4 solution, followed by a capillary water absorption test. The study was conducted to test the durability of recycled concrete, establish the initial capillary water absorption prediction model under freeze-thaw in different media, and analyze the internal structure of the RAC group after freeze-thaw using SEM. The test results showed that the composite-modified water absorption decreased the most, which can effectively improve the durability of recycled concrete, and the chloride salt caused the greatest erosion of recycled concrete and had the least clear water. The predictive model has high accuracy and can be used as a reference for capillary water absorption experiments on recycled concrete.

Salt damage caused by the complex interaction between water and salt in the heritages is the main factor that deteriorates the materials and destroys the historical information of the relics. The influence of environmental conditions, especially humidity, on salt damage of heritages has been emphasized by many researches. In this study, the water-salt migration characteristics in soil columns under different humidity were studied by laboratory tests. First, water vapor adsorption test was carried out to investigate the soil samples adsorption capability in 6 relative humidity conditions (RH11%, RH23%, RH43%, RH60%, RH75%). There is a linear relation between relative humidity and water vapor absorbed by soil, and the water vapor adsorption curves of samples can be well described by first-order exponential attenuation equation. Second, the water content and conductivity distribution within samples (hygroscopic and non-hygroscopic samples respectively) were investigated after capillary migration tests using 4 types of saline solutions (0.2 mol/L NaCl, 0.2 mol/L Na2SO4, 0.2 mol/L NaCl Na2SO4 mixed solution and distilled water). Results show that high conductivity appears on the top of most samples, and the values have a correlation with type of capillary migration fluid: NaCl > Na2SO4 > NaCl-Na2SO4 > H2O. In addition, the distribution of water content and conductivity becomes complicated under different relative humidity conditions.