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HARDCORE

The term ‘hardcore’ refers to the mass of solid materials used as a make up, formation material to raise levels, fill irregularities in excavations and create a firm and level working base onto which heavy load-bearing surfaces such as stone or concrete can be laid. The hardcore then helps evenly spread imposed loads.
Hardcore may be used in the formation of roads, paving, driveways, foundations, ground floor slabs, and so on. It may also be used on its own to form a temporary road surface on construction sites.

A variety of graded materials can be used to make up a hardcore layer:

Construction waste such as brick and broken tiles.
Gravel.
Quarry waste.
Crushed rock.
Clean, graded concrete rubble.
Blast furnace slag.
Colliery spoil.
Oil shale residue.
Pulverized-fuel ash.

Materials need to be sufficiently hard as well as being capable of being compressed (rammed to form a compact base) before the upper layer is added. This removes gaps or voids which could otherwise threaten the supportive properties of the hardcore layer.

They should also be resistant to deterioration, chemically inert, should not be absorbent and should not be affected by the presence of water (for example, colliery shale expands when moist).

Quarry waste is a good source of hardcore material, although care should be taken not to include waste from gypsum mines. This is because such waste often contains a mixture of limestone and gypsum which can attack concrete. Similarly, concrete rubble may lead to a risk of sulphate attack if it contains gypsum plaster. Construction waste can contain timber which may deteriorate and can spread rot. Substances such as colliery spoil may contain soluble sulphate which, if it reacts with water, can infiltrate and damage cement.

The type of construction, expected load and probable stresses will determine the appropriate thickness of the hardcore layer that must be used. Typically it is laid in well-compacted layers of 100-150 mm.

Xiangai Digital Base Your Building Partner delivers to you the Best Quality Ever All Building Materials, hardcore, Ndarugu building materials, Ukambani Sand, Naivasha Sand,foundation stone……..

 

 

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BLACK COTTON SOIL

Plinth Protection

Plinth protection in the buildings is provided for preventing water entering into the foundation. In normal cases, 0.9 m to 1.2 m wide plinth protection is provided with brick bats. But in case of black cotton soils, due to expansion and drying characteristics of soil, such plinth protection gets damaged within a short time. Rain water pipes are also left on plinth protection. Plinth protection acts as very important barrier in the areas of black cotton soil to prevent water coming into contact with black cotton soils. Thus plinth protection should be impervious and as wide as feasible. 2 to 3 m wide plinth protection in such conditions is recommended considering site requirements, space availability and depth of black cotton soil. RCC plinth protection with lime concrete as base concrete is recommended. No space should be left for planting trees or plants near plinth protection as the plantation requires water and such water is harmful to the structures. It should also be ensured that in no case, level of plinth protection is lower than the adjoining ground as there is a possibility of a crack between wall and plinth protection from where water can seep through. It is also better to cast RCC horizontal plinth with drain and vertical plinth.

Vertical Plinth

Vertical plinth along with horizontal one is more effective in preventing water into the foundation as minor cracks develop at the junction of wall and horizontal plinth protection due to construction sequence and different materials. Thus, the water flowing along the wall enters into the foundation. Also in case of flooding around the building, and even due to splashes during heavy rains, there is a likelihood of water entering into the foundation through brickwork. Vertical plinth in such conditions also keeps water away. Such plinth can be provided in the form of stone cladding supported on plinth protection. RCC wall connected with plinth beams overlapped over plinth protection is very helpful as it works like an umbrella over junction of plinth and the wall. It is to be ensured that no flooding occurs around the building.

Vertical Barrier and Drains

Vertical barrier on the outer edge of the plinth monolithically cast with the plinth also lengthens the flow path and keeps moisture away from the foundation. Though, the depth of vertical barrier depends upon active zone but more the depth, higher the length of the flow path. Since the drain also helps in keeping the moisture away, vertical barrier can be used as a part of the drain. Inner wall of the drain can be constructed monolithic to the plinth protection. More the depth of the drain, higher the length of the flow path and better to keep moisture away from the foundation. If geo-membranes are used vertically, they will also be effective but it is to be ensured that they do not get punctured from the pressure of filling material and have leak proof joints. In case, wide horizontal plinth cannot be provided due to site constraints, long vertical barriers should be provided to lengthen the flow path.

Damp Proof Course (DPC)

Normally, DPC is provided with cement concrete over which a bitumen coating is done. During continuous rains, water flows along the surface and enters the foundation along the external surface. Therefore, it is recommended that RCC damp proof course should be provided to make it impervious compared to ordinary cement concrete and vertical plinth provided up to DPC.

Road and Plinth Protection

If the road/pavement surface is near the building, no space should be left between plinth protection and the road/pavement surface. The space should be paved to avoid water to seep through by continuing the road/pavement surface up to plinth protection. Leaving no space between the plinth protection/building and road lengthens the flow path.

Rain Water Pipes

Normally rain water pipes are left on plinth protection. When plinth protection gets damaged, water percolates into the foundation soil. Therefore, rain water pipes should be connected into chambers and chambers to the drain. In internal courtyards, rain water pipes are to be connected to outside drains. If these pipes are left inside and water is not properly taken outside, this leads to heave of floors, cracks in walls and other damages to the structure. It is always better to pave all the internal courtyards so that water is kept away from the foundation as well as floors.
Horticulture Works

Horticulture works are undertaken in the buildings for the beautification and also for better environment. It must be understood that the horticulture works require water throughout the year. Hence, water comes into contact with adjoining soil. Since in case of black cotton soil, water is to be kept away from the structure, it is better to plant trees away from the structures. Therefore, plantation is to be carried out in consultation with civil engineers else the plantation helps in damaging the structure in such soils due to moisture attraction. Trees should be planted away from the buildings and on other side of the road.

Base Concrete and Filling Under floors

Normally cement concrete is provided as base concrete. In black cotton soil, lime concrete is effective as it alters the characteristics of the expansive soil. Hence, lime concrete should be provided as base concrete in place of cement concrete. It is said that 2-6% lime prevents swelling characteristics of expansive soil. Below footing level and floors, layers of non swelling soil mixed with moorum or WBM material are effective and are better than sand filing.

A combination of RCC damp proof course, vertical plinth, and monolithically constructed RCC horizontal plinth with RCC drain helps in preventing water entering into the black cotton soil. Wide horizontal plinth protection large depth of monolithically cast drains help in lengthening the flow path to avoid water entering into active zone.

Xiangai Digital Base your Building Partner is there to guide you, and supply you with the best quality building materials.

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Biological septic tank will save you space and money


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Measuring only a metre cubed for a domestic house, the modern biological tank is relatively small. With a capacity of 1,000 litres, the tank, can serve up to 40 users. A slightly larger tank, measuring cubic metres can serve a building of up to 100 users. Larger biological tanks are available for institutions and commercial buildings.

Concerned about the crowding in some urban estates and the need for a clean environment, Improved method of waste disposal. For some years now, Xiangai Digital base your building partner has re-invented the way households handle sewage. Instead of the traditional septic tanks, which are usually smelly, fill up after a couple of years and take up considerable space,Xiangai Digital Base has introduced biological septic tanks that use bacteria to digest organic waste on site.

“We felt it was time to design a system that could dispose of waste in a more eco-friendly way, and with fewer headaches for our consumers,” says Mr Boniface Waciama, the director of Xiangai Digital Base your building partner.

A marketer with the waste-water management firm, says their septic tanks are becoming popular, with some users even opting to convert their septic tanks into the modern biological ones by fitting a bio-digester. The increased demand, she says, is because the biological septic tanks are comparatively smaller, don’t smell, and never get filled up, so there is no need for exhauster services. “All these result in big savings for a homeowner in the long run,” she notes. Rectangular tanks are made of highly vibrated concrete. They consist of a body, inlet and outlet baffles (devices used to restrain the flow of the water). The tanks are designed to be gravity powered and are suitable in high water table and inundating areas. They are structurally sound, water-tight, corrosion and buoyancy resistant.

The biological septic system consists of three parts: A grease interceptor, a biological tank and a soakage drain. The system also divides the waste into grey water and black water. The latter is effluent that has come into contact with faecal matter, while the former is water from the bathroom and kitchen sinks and laundry machines. “Grey water is a combination of fats, oils, grease, waxes and detergents, which makes it chemically unstable” explains the experts. “It is thus not allowed into the digester. Instead, it is passed through a grease interceptor to rid it of oils, which can be harmful to the environment. Thereafter it is directed to the soakage pit.” The soakage pit (or French drain as it is also known), is a tank where the accumulated water seeps into the ground. Black water, on the other hand, is chanelled into a bio digester. Here, the bio digester uses naturally occurring anaerobic bacteria to treat the black water by digesting the faecal matter while eliminating pathogens (disease-causing organisms). The faecal matter and other organic matter settle at the bottom of the tank through sedimentation and are converted by the bacteria into water and gases.

Xiangai Digital Base your building partner, The best quality Building Materials.

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Single Piles and Pile Groups

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Pile Groups, Laterally Loaded Piles, P-Y Curves and Rock Socket, Pile, Capacity, Engineering, Software, Load, Calculate, Laterally, Loaded, Analysis. Xiangai Digital Base is a building supplying company with the aim of delivering the best quality building materials and developing geotechnical design and analysis programs. Innovative Geotechnics provides innovative geotechnical design tools for soil-structure interaction and deep foundation problems such as single piles or pile groups under lateral and vertical loads.

Innovative Geotechnics provide geotechnical design tools for soil-structure interaction problems such as pile groups, laterally loaded piles, nonlinear p-y curve generation and rock socket design, including single piles or pile groups under lateral and vertical loading based on finite element method. Our programs are focused on the geotechnical analytical knowledge, improving user engagement and reducing potential input uncertainties. All geotechnical programs and software adopt simple input interfaces for the users to interactively enter the analysis information such as soil layer information, soil properties, and foundation design parameters.
Key Features of Deep Foundation Design Programs

Nonlinear behavior of soils and rocks for pile foundations under axial and lateral loading Easy input of soil layers, structural and geotechnical properties and external loads Finite element method based on Garlerkin formulation instead of lumped springs at the element node like the conventional finite difference method; Powerful nonlinear solver based on the arc-length approach; Nonlinear bending stiffness of piles; Both static and cyclic behavior of soils for laterally loaded piles based on p-y curves; Displacement loading for piles subject to soil movement based on the approach of Byrne et al.

Easy input of soil layers, structural and geotechnical properties and external loads Finite element method based on formulation instead of lumped springs at the element node like the conventional finite difference method; Powerful nonlinear solver based on the arc-length approach; Nonlinear bending stiffness of piles; Both static and cyclic behavior of soils for laterally loaded piles based on p-y curves; Displacement loading for piles subject to soil movement based on the approach of Byrne et al. Easy to add, delete and insert different layers for soils and rocks; A wide range of pile head loading conditions; Easy to define pile batter and ground surface slope for laterally loaded single piles; Easy to define various pile section types such as circular, rectangular, octagonal, H shape, Pipe and user-defined sections; Easy to define varying bending stiffness along the pile length; Easy to define pile spacing and pile layout for pile groups.

Efficient and powerful visualisation of analysis results through well-designed graphics outputs Extensive built-in load transfer curves for soils and rocks Plotting nonlinear p-y and t-z curves for any location along the pile length; Plotting deflection, bending moment, shear force, soil reaction, shaft and end bearing resistances and many other results; Displaying pile load and settlement curve at the pile head for axial and lateral loading; 2D and 3D graphics outputs for the pile group analysis results.

Innovative Xiangai Digital Base is a building supplying company with the aim of delivering the best quality building materials and developing geotechnical design and analysis programs. Such as soil-structure interaction and deep foundation problems such as single piles or pile groups under lateral and vertical loads.

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Required Use of Flood Damage-Resistant Materials

Due to flood Xiangai Digital Base has taken another wave of selling the best water resistant materials. We’ve been told to get used to flooding. Whether or not the latest floods were caused by climate change, this winter has reminded us that floods are and will continue to be a fact of human existence, especially if we continue to build on flood plains and due to increased extreme weather events as predicted in a changing climate.

Floodwater is assumed to be considered “black” water; black water contains pollutants such as sewage, chemicals, heavy metals,or other toxic substances that are potentially hazardous to humans.

Flood [damage]-resistant material is defined by the NFIP as “any building product [material, component or system]capable of withstanding direct and prolonged contact with floodwaters without sustaining significant damage.” The term “prolonged contact” means at least 72 hours, and the term “significant damage” means any damage requiring more than cosmetic repair. “Cosmetic repair” includes cleaning,sanitizing, and resurfacing (e.g., sanding, repair of joints, repainting) of the material. The cost of cosmetic repair should also be less than the cost of replacement of affected materials and systems. In addition to these requirements, individual materials that are considered flood damage-resistant must not cause degradation of adjacent materials or the systems of which the material is a part.

All building materials below the Base flood elevation must be flood damage-resistant, regardless of the expected or historic flood duration. For example, buildings in coastal areas that experience relatively short-duration flooding (generally, flooding with a duration of less than 24 hours) must be constructed with flood damage-resistant materials.

All construction below the Base flood elevation is susceptible to flooding and must consist of flood damage-resistant building materials. The purpose of http://www.xiangaidigitalbase.wordpress.com “materials resistant to flood damage” and how and when these materials must be used to improve a building’s ability to withstand flooding